You can save on the incorporation services by downloading forms directly from a given state's Secretary of State site. Most states have clear instructions on how to fill everything out and where to submit the paperwork and payment. Incorporation service companies are great, but if you're trying to bootstrap a startup every dollar counts.
Additionally, if there will be multiple owners/members of the new entity I strongly suggest buy/sell agreements (basically a contract stating who can sell their interest and when and to whom - saves a lot of headache later to figure these things out up front).