How can I do a let's play

I've been wanting to do Let's play for months, I have over 300 games on my computer (99% of them being on steam)http://steamcommunity.com/profiles/76561198001428746/games?tab=all

I have a pretty good computer but I haven't found a good way to set up let's played. Most tutorials I've found have been lack luster but I just wanted to get your guys opinions of a way to stream or even just record and upload it to youtube high quality play throughs of games

If anyone is knowledgeable they could also just PM me