This is an excellent question. There are several things that you can do to help students through the difficulties of reading. In light of this, let me give you a few examples.
First, you can tell students that reading is, indeed, difficult. This confession might encourage them. They will know that they are not alone.
Second, starting with something easier would probably encourage students press on. In addition, a time in the class where students can share and discuss what they have read might also make the reading fun.
Third, one strategy in reading well is to keep reading, even if things are difficult. In other words, students do not need to stop every time something seems difficult. Part of the reason for this is that later portions of text often times grant illumination to earlier parts of the text. So, one technique is to keep reading.
Fourth, find out what students love. If you can assign books to them that they love, then it will encourage them to press on in the reading process.
Depending on the age level, there are various ways to help a student.
First, if you are an elementary teacher, you can give an assessment to see if there are any problems with letter naming, sounds and phonemic awareness.
Next if a student does not seem fluent because of problems with the above named items, give the student practice by going over letter names, sounds and blending. Songs and poems that focus on a letter would be appropiate also. A teacher can also give more practice by allowing a student to read decodable books that usually focus on a letter with repetitive text that also include sight words.
Reading with a partner would also be helpful.