In The Hobbit, Tolkien gives the reader a dragon-sized wealth of information concerning Hobbits, Bilbo Baggins in particular. Hobbits are known for their predilection for living in cozy, warm holes in the ground; their preferences concerning their domiciles suggest a deep love of comforts and easy-living as well as their appreciation of natural beauty. The fact that hobbits deemed their best rooms to be the ones with windows "overlooking [the] garden, and meadows beyond, downward sloping to the river" suggests their love of the outdoors and nature (Tolkien 3).
In appearances, Bilbo Baggins was very much the picture of an average hobbit. Hobbits have tough, "leathery soles" to their feet, which are covered in curly "brown hair like the stuff on their heads," and the absence of hard-soled shoes give hobbits an uncanny ability to move quietly or remain unseen from "large stupid folk (4). Hobbits, in general, preferred keeping to themselves and abstained from any foolishness like adventures. Bilbo was not an exception to this rule, even though his heritage as a Took did suggest an occasional longing for adventure. Ultimately, Gandalf recruits Bilbo to be their burgler on the dwarves' journey, sensing that the quiet hobbit may yet prove to be an asset.
Bilbo Baggins was the Central character of The Hobbit, written by JRR Tolkien, and he lives in the Shire. He was the Uncle (more of a distant cousin, but always called Uncle) of Frodo Baggins and a respectable, typical Hobbit. His father was a Baggins, and his Mother was a Took. The Tooks were more adventurous than Baggins' and this is what made Gandelf convinced that Bilbo was perfect for the Quest of Erebor and he joins Thorin's company of Dwarves setting out accross Eriador. Bilbo is the first ring-bearer to give up the ring voluntarily, notable in Middle earth history.
Most Hobbits are between 2-4ft in height, sometimes less than 3ft if they are older. They usually have caucasian skin colours (light brown to white) and dark brown curly hair (or white and grey in their older years). Their feet are hairy and sometimes quite large, although Tolkien never really talks about large feet, so it's unclear whether that is a true characteristic. They live in the Shire, or sometimes in Bree-land, an eastern post near the main intersecton into Eriador. Only adventurous Hobbits really ventured that far. Hobbits were considered the closest thing related to Man, in middle earth.
The above responses contain valuable information, but I just wanted to emphasize the note Greenlightshade brought up regarding Bilbo's lineage; the Tooks tend to be more adventurous than the Baggins, but all hobbits are characterized as prioritizing comfort over success or ambition. Smasella's answer is something with which I would agree, but Bilbo is a notable exception to the "mold" of hobbits as prescribed by Tolkien, in that Bilbo travels a lot in The Hobbit—he is notable because this is extraordinary for hobbits and for Bilbo himself. Natural, unfettered lives (as far as technology is concerned) are the goal of many hobbits, who occupy spaces like the Shire because they are more remote in the scheme of Middle Earth, which affords them a boundary of tranquility. In The Lord of the Rings there is more mention of hobbits like Samwise, or Merry and Pippin, who share the hobbit characteristic of preferring to stay home and enjoy ale or a pipe—but the most logical reason for the hobbits in these tales to leave their beloved homes is because it is the only way to ensure that they will be able to enjoy serenity there in the future. Hobbits like to be comfortable.