I suggest newbies seeking info on building out 80% receivers try footpounds.com first.

That site has answers to many of the 80% receiver questions that seem to crop up here on a daily basis: where to buy an 80% receiver, what is needed to complete an 80% receiver, what are the laws regarding 80% receivers, etc.

If you have a question while building out an 80% receiver I'm sure that there are at least a dozen members here would love to help, but if you just need some foundational info, please try there first.