I've just recently purchased all the parts to assemble two AR rifles.  The uppers are complete and assembled already, all I need is to complete the lower assemblies.  I was going to have a trained gunsmith take care of it, but after researching and watching several videos, it doesn't look all that difficult if you have the proper tools.  I've been researching tool kits, specifically those that have the punches for the pins/roll pins and that refer to being for AR's.  My questions to those that do this on a regular basis are:  1.  Should I attempt it without proper training or oversight?  I feel that I am a competent person with tools.  And #2.  Is there a particular kit made that has everything included, but not loaded with a bunch of common tools I probably already own.  
I've seen the Wheeler Engineering AR-15 kit and the Obsidian Arms AR-15 Armorer's Punch Set, then just a bunch of punch sets sold separately.  
Thanks, I appreciate your assistance.

The lower is much easier to assemble than the upper.  I'm sure there is a kit of everything you need, but it may be cheaper to piece it together.  The tools I used are:

1.  Basic roll pin punch set.  I got the Lyman 4-piece set off Walmart.com.
2.  A rubber/brass mallet.
3.  An allen wrench (I think I used 1/4") is helpful for installing the front pivot pin detent and spring.  So is a tiny flathead screwdriver.  You probably already have these.
4.  Armorer's wrench for turning the castle nut.  There are lots available from many sources.
5.  Block that fits in the magwell.  Very helpful to hold the receiver while you work on it.  I ordered mine from Plastix Revolution, but they are very common.

I think that's pretty much it.  Electrical tape is useful to cover areas so they don't get marred while installing pins.  I also used a block of wood to support the triggerguard ears, you don't want to break those off.

1/4 clevis pin & punch or even small Allen wrench make 's installing the pivot pin installation easy.