The instructions are very good. You should probably read through them once or twice ahead of time.
http://manual.prusa3d.com/c/Original_Prusa_i3_MK2_kit_assembly
Make sure to look through the comments too. They often provide great advice. A set of calipers is useful for a few steps if you have some, and if not you'll probably want some anyway for 3d printing. Building it is totally worth it and makes diagnosing problems a lot easier. Set aside a full day or a couple days and don't rush it and there shouldn't be any problems.
http://manual.prusa3d.com/c/Original_Prusa_i3_MK2_kit_assembly
Make sure to look through the comments too. They often provide great advice. A set of calipers is useful for a few steps if you have some, and if not you'll probably want some anyway for 3d printing. Building it is totally worth it and makes diagnosing problems a lot easier. Set aside a full day or a couple days and don't rush it and there shouldn't be any problems.