Your thesis statement should be a clear statement of the point you are trying to make, stated as a fact. I think computers help students. This statement makes your point, but is is not very specific or forceful.
Computers are helpful to students.
This one is better because it has stated the point as fact. However, it is still not very specific. By writing something a little more specific, this thesis can really control the flow of your essay. Computers are very valuable to the modern classroom. These are discussed in the body of the paper.