What was Jabez Wilson's job in the Red-Headed League?

There is a short answer and a long answer to this question.

The league was ostensibly a society established by an eccentric rich man that benefited red-headed men by employing them. The league hired Jabez Wilson to come to its office and do bizarrely minor clerical work: spend the hours of 10-2 copying pages from Encyclopedia Britannica. Jabez spent seven weeks writing before he was informed that his services were no longer needed, because the league had ceased to function.

The long version is that Wilson's actual function for the "league" was dupe. The league did not exist, although someone did rent an office and he did go there and copy the book. Wilson had a real job, or rather business, that of pawnbroker. It was this business, especially its location, that made him useful to the people who invented the deception. They were paying him to be away from his shop so they could get up to no good there.

Jabez Wilson is the person who initially comes to Sherlock Holmes as a client in "The Red-Headed League" by Sir Arthur Conan Doyle. He himself has red hair. His assistant, Vincent Spaulding, alerted him to an advertisement in a newspaper for a position working for the Red-Headed League that appeared to offer a fairly substantial salary for a minimal amount of work. Wilson applied for and obtained the position. 

The job was a very odd part-time one. It required his showing up to an office from 10:00 a.m. until 2:00 p.m. every day, before the start of his work in his pawn shop, which was his main business. When he was in the office, he was required to copy out pages from the Encyclopaedia Britannica by hand. He does this for several weeks progressing almost halfway through the "As", and then arrives at the office one day to discover that the League no longer exists. Puzzled by this turn of events, he talks to Holmes. 

What is the red-headed league, and how does Jabez Wilson join it?

Jabez Wilson finds out about the Red-Headed League through an advertisement which had been placed in the newspaper. This advertisement said that a salary of £4 per week would be payable to members of the League who met its conditions, which were:

1. Members had to be sound in body and mind;

2. Members had to be over the age of twenty-one years, and;

3. Members had to be red-haired.

The advertisement also stipulated that membership of the league was open only to men, suggesting that red-haired women would not be eligible.

£4 a week was a significant sum in those days, which is why the advertisement caught Wilson's attention. Those wishing to become a member of the League would have to perform "nominal services" and would have to make an application in person at a stated time and place.

The League, supposedly, was founded by a red-haired American gentleman who wanted to leave his fortune to other men with red hair. When Wilson applies and is accepted, he is told that the work entails copying out the Encyclopaedia Britannica four hours a day.

This, naturally, struck Wilson as strange, particularly when, one morning, he arrived and found the offices closed and locked. In the course of his investigation, Holmes discovers that the League is in fact an invention; the criminals who thought of it had simply wanted to keep Wilson out of his shop so that they could receive stolen goods from a bank vault through a tunnel in the floor of said shop.

In "The Red Headed League," how do Jabez Wilson's traits influence the story?

Jabez Wilson is also a widower and pawnbroker. He isn't a very bright man, but he does love money, allowing him to be used by Clay as part of a scheme to rob a bank. He tries to get something for nothing two times during the story.

John Clay is a criminal who has eluded the police for years. Holmes considers him to be intelligent. We know he comes from royal blood, has had an aristocratic education, and is egotistical about his abilities as a criminal. This makes us think Clay gets involved with crime for the challenge of the game and not just for the money. He is imaginative and a formidable opponent for Holmes. He and Holmes are alike in many ways except when it comes to their motives and the morality of their actions.

Sherlock Holmes is known for his ability to tell a great deal about a person by observing his/her little idiosyncracies. He's very intelligent and has knowledge about insignificant topics and previous criminal cases. He no doubt gets pleasure from the mental game of solving a crime. He takes pride in his mental abilities that enable him to solve a crime. Holmes also is unselfish when he tells Merryweather he wants no reward beyond his expenses for stopping the robbery.

Merryweather is respected as the director of the City and Suburban Bank. He's overconfident, worrying more about missing his card game than about his bank vaults.

What details about Mr. Jabez Wilson's appearance in "The Red-Headed League" reveal his character? Explain.

"I did not gain very much, however, by my inspection. Our visitor bore every mark of being an average commonplace British tradesman, obese, pompous, and slow. He wore rather baggy gray shepherd's check trousers, a not over-clean black frock coat, .... A frayed top hat and a faded brown overcoat with a wrinkled velvet collar lay upon a chair beside him."

The question is related to the appearance of Mr. Wilson and whether accurate inferences can be drawn about him as a person based on the description.  As Watson, the narrator, points out there is very little to gather from the description of Mr. Wilson.  However, it is possible to gain a few details.  It is stated he has the look of a commonplace tradesman, is obese and pompous.  The baggy trousers and not overly clean coat suggests he is not particular about his appearance considering the importance of the meeting with Holmes.  The frayed hat and faded overcoat suggest Mr. Wilson does not possess any wealth.  This is also hinted at in the mismatch of colors and cloth.

While it is possible to gather a few details and form some assumptions upon his habits based on his appearance, there is not enough information to form a complete picture of Mr. Wilson.

In "The Red-Headed League," what is Jabez Wilson's profession?

Jabez Wilson is a pawnbroker. He explains his occupation and his unusual problem to Sherlock Holmes and Dr. Watson at Holmes' lodging in Baker Street.

"I have a small pawnbroker's business at Coburg Square, near the city. It's not a very large affair, and of late years it has not done more than just give me a living. I used to be able to keep two assistants, but now I only keep one; and I would have a job to pay him but that he is willing to come for half wages so as to learn the business."

A small pawnshop is an ideal setting for the mystery Doyle is creating because such an establishment would not have a steady flow of trade but only an occasional caller who wanted to pawn some trinket or one who wanted to redeem something. In such a shop, the doorbell would ring whenever a customer entered, so there would be no need for anyone to stay posted at the counter. This, as the cunning John Clay recognized, would give him plenty of time to go down into the basement and dig away at his tunnel, if only he could find a scheme to get his employer away from the premises for some time during the day.

Doyle does not describe the interior of the pawnshop, but he does capture the appearance and atmosphere of the quaint, sleepy old Saxe-Coburg Square where Wilson's struggling business is located.

"Let me see," said Holmes, standing at the corner and glancing along the line. "I should just like to remember the order of the houses here. It is a hobby of mine to have an exact knowledge of London. There is Mortimer's, the tobacconist, the little newspaper shop, the Coburg branch of the City and Suburban Bank, the Vegetarian Restaurant, and McFarlane's carriage-building depot."

One of the main attractions of the Sherlock Holmes stories is that they take the reader in imagination into many different parts of England, both the interiors and exteriors, and in city and country, opium dens and majestic manors, where every kind of man and woman is to be met. Jabez Wilson, the gullible pawnbroker with the flaming red hair, and John Clay, the aristocratic burglar who has connections to the infamous Dr. Moriarty, are just two such unique characters.