My name is Cash, I live in Estacada, Oregon, and I've been a star wars fan since I was a youngling. I would love to get more info on how to get a set of stormtrooper armor together, and also on officially joining the 501st legion. Any tips and advice are more than welcome! 
Hi Cash:
First off, welcome! On to the links:
I can get you some quick links to get you started on your reading and research:
501st FAQ
http://www.501st.com/faqs.phpInformation on 501st costumes, note that there are a few different areas for what the average fan calls a "stormtrooper"
http://databank.501st.com/databank/Costuming:CRL Information on "stormtrooper" costume details:
http://databank.501st.com/databank/Costuming:FISD_CRL Note that each movie has slight changes from 1 move to the next (and the original New Hope has a couple...Stunt and Hero and then, separately, sand troopers and tie fighter pilots etc)
Sandtrooper (Tatooine) is elsewhere, as are Tie Fighter pilots, etc.
http://databank.501st.com/databank/Costuming:MEPD_CRLhttp://databank.501st.com/databank/JRS_CRLFor 'stormtroopers', the ultimate site of information is here:
http://www.whitearmor.net/forum/ That site can help you in many ways.
My general advice is not to rush any decision. It takes a bit of time and/or money (and usually both) to figure it out so think it all through. Look at the websites and ask yourself what type of costume you like (you might discover it's not even a stormtrooper...maybe it's a Sith Lord or, gasp, some Rebel scum). If it's a stormtrooper, maybe it's old school/Rogue 1 "storm trooper" or maybe it's a prequel Clone or The Force Awakens "First Order". Quite a few ways to go there.
Part of your research should also be looking at size, if you are a larger person, there are some builds that can accommodate that as well. Everybody will recommend you avoid buying from Ebay. And everyone will advise that just because someone touts an item they are selling as "501st approved", doesn't mean it is, and it doesn't mean it would be for you. Even if it's pretty much approve-able, it still has to fit you (for example). I would stick to this site for guidance:
http://www.whitearmor.net/forum/ But step 1 is checking out the sites above and then spend some time researching and reading up on it.