The first question there is a big topic and one that requires a lot tutorials and a lot of trial and error to fully learn the process. There are many decent tutorials around some you can find here http://www.learning-maya.com
As for your second question, Normal maps and bump maps are not the same, but they both work in similar fashion. Normal maps can be used to simulate various details and generally give much better results then a bump. Bumps are ok for adding some texturing details but generally don't do fine details very well at all. Plus the process involved in generating these two maps is drastically different.
I have found that as technologies change and evolve I see less and less use of the bump map and much more use of the normal maps. This mainly because of the level of detail a normal map can handle.
The high detail comes at a cost though, and that is that normal maps are generally much more time consuming to produce because you usually have to model a very high poly mesh and then project that onto a lower poly mesh.
So it becomes a balance of figuring out which pieces get a normal maps, a bump maps or nothing at all. Experience I think is the key here, but I would say a good rule of thumb is, if its in the players face, normal map it; if its always going to remain at a short distance, bumb map it and if the player never gets any where near it, then it gets nothing at all. This can change of course based on the project but generally that seems to be the way of it.
Hope that helps