You should check out the online courses in Marketo University: learn.marketo.com.
I'd recommend starting with New To Marketo (formerly Basics I), which goes over the basics. If you type it into the search, it should come right up.
I agree. learn.marketo.com is good.
You can also visit: Welcome to Marketo Docs - Marketo Docs - Product Docs This is Marketo's documentation which is getting much better.
Josh Hill also put together a guide similar to what you might be looking for. It can be found: http://www.marketingrockstarguides.com/marketing-rockstars-guide-to-marketo/
It is getting a little outdated, but is still useful.
Hope this helps.
Yeah, the Guide is about 50% out of date now, but key best practices on admin, scoring, etc are still valid.