If you watch a DIY program on TV then they make it look so easy, but it is a lot more involved than most people think. For example putting up a shelf, this is the kind of DIY task that people try themselves, and on TV they would do it in 2 minutes, but when you try to copy them at home then it ends up either crooked, or just falls off the wall when you put anything on it!
Before you even consider putting up a shelf then first of all think about how much load the shelf is going to take, then buy a kit that has enough thickness in the actual shelf, and enough strength in the fixings and brackets to support that weight (yes books are heavy!). You can get fancy shelves with no visible brackets, or ones with fancy twirled brackets etc, but often they sacrifice strength for design so they are only good for light loads.
Once you have your kit then you need to find somewhere suitable to position it on the wall, make sure you think about if there are any pipes or cables behind where you want to mount it. You can actually buy devices that promise to find cables and pipes, and they can also be useful for finding the wood inside the wall to secure to, but they don’t always work. So look for sockets and light switches that will have cables going to them, and try to get a clear area.
Once you are happy that there are no pipes or cables to be hit then you need to consider how to fix it, with a brick wall then you need to drill it and use plugs, with a plasterboard and stud wall then you are going to struggle more. You can get dedicated plasterboard fixings, but they won’t be able to take a great amount of weight, instead you are better off looking for the studs in the wall that you can screw into, that will give a good fixing.
When you have planned how to fix it, then drill and secure one hole in the bracket (preferably the bottom one) and then hold the other bracket up with the shelf on it and a spirit level on top of that. Then get it level (you might need help at this point) and mark up the second hole on the bracket you are working on, and the holes on the other bracket too. Then you need to put all the final fixings in for the brackets and attach the shelf and you are done. Now you can stand back and admire your handiwork, and preferably give it a bit of a try to see that it can hold some weight before you put anything valuable on it!
If you are serious about DIY then you need to get yourself a decent cordless drill like the Makita BDF452HW drill set from Amazon.com.