Read the stickies at the top of the forum.
Figure out what you want to cool.
Determine how much heat in Watts you will need to remove.
Decide what level of fan and pump noise is tolerable for you.
After the above is complete figure out what combination of RADs, fans, pumps, blocks & REZ, will get you the results you want/need.
Pick a case that it will all fit in, and start buying stuff.
For your first build keep it simple.
After you have read the stickies on water cooling. You will have a great base of knowledge to make educated choices and ask questions.