Login integration

Hey there everyone!

I am sure this question has been asked a million times but I have spent more than a hour now searching the web for an answer. I have a hand-coded membership system on my site. I would like to integrate my WordPress installation with. All I need to happen are two things:

1) A new WP account to be created when a new user signs up on my site.
2) The user to be automatically logged into their WP account when they log into my site.

That shouldn’t be too difficult to do but for the life of me I can’t find any documentation on how to do this. Perhaps its just not my day. :/ Thanks for taking the time to read this.