1. LLC FAQ http://www.sos.ca.gov/business/llc/llc_faq.htm
2. LLC Form (1 pg) http://www.sos.ca.gov/business/bpd_forms.htm (search for LLC-1) — $70
When you get approved, you will need to submit a Statement of Information which costs $20.
3. If you don't make money you can waive the first year's min. franchise tax of $800.
4. Lawyers will usually help you for free if you are starting a legit business, but it will be costly (we just got a bill for $10k for starting up our s-corp).
5. Good luck!
Don't waste your money or time on third parties for something so simple. (Corporations are more serious, due to having stock, and you probably ought to have a lawyer involved, so online incorporation services are probably never a great idea.)
However, since you have a partner in this LLC, the really important thing is to set up your "operating agreement". This will decide how the company is controlled, revenue shared, what happens when someone leaves... etc. Don't wait until someone wants to leave or you're making decent $ before trying to figure this out. You can file the agreement with the state, too.
If I were you I would write down in your own words what you want in the operating agreement and then take the money you saved from NOT using legalzoom and have a lawyer codify what you have into legalese.
I summarize some of the tradeoffs in the following ...
FYI: You can defer that $800 payment if its your first operating year.
Within the last year I read some research suggesting a further refinement that better ensures the partner who valued the business highest winds up with it... but can't find the reference right now.
The forms are easy enough to fill out yourself.
Some VCs prefer LLCs because it gives them the risk-minimizing benefits of a corporation, while at the same time giving them a hand in managing the business (a la partnership form). HOWEVER, many VCs, especially the smaller ones, are unfamiliar with LLC law, and avoid it b/c they don't know about it. Some VCs prefer S-Corp because it ideally gives them access to the founders' personal assets, but in practice, a bankruptcy court will try very hard to deny this benefit.