OK I have 3 patents...The first thing is find a good patent Attorney and be ready to pay. Dont go with the cheapest because a patents enforability is all in how it is written, it is a true artform.
Make sure you have all your notes,dates,prototypes etc. in order and if you can afford it (My first patent was around $3500US) go for your international patents at the same time. The international patent process is way diffrent than US.
Example I was able to obtain a patent for a tilt regiristring process..i.e. shake a arcade controler and the controler registers 'TILT" in a game...Because I had beta tested it to the public, while I recieved a US patent, I could not get an International Patent because I hadn't applied for it with in, I think it was 6 months.
Anyway I have a good Patent Attorney and can recommend him pm me if I can help