Typically these rifle kits include a fully assembled (barreled) upper receiver, a handgrip and stock, and a bag of internal parts for the lower receiver that you bought from an FFL. Detailed instructions are available on the web. No need for special tools, except maybe a set of roll pin punches. Standard punches work, but increase the chances of scratching your receiver. You can minimize scratches by liberally applying masking tape around the roll pin holes.
I recommend not going with the lowest price parts kit, unless you know what you're doing. Those vendors seem to skip over the quality steps, leaving you to do that for them. I had to rebuild a new bolt from one such vendor. I took me a while to figure out the problem (broken gas check ring and defective extractor spring).
Do your research before buying. Also check out J&T Distributing.