My advice to the new/aspiring RPG writers is heed the words of the wise folks found above (judge my own as you will). Just some comments to springboard off of some of Morgenstern's...
Morgenstern said:
Lots of good advice already, but do not underestimate the importance of the shmoozing skill set. There is a lot of talent out there, so learning how (and where) to show off yours is an essential step.
I couldn't agree with this more. Of course, Morg found me in just this way, when I brought him 100 pages of primordial game material for Spycraft and a pretty good idea. You've got to bring something to the table, and I think it only helps your case if you can show you are a reasonable human being at the same time. Go to a show, and talk with the people there. Then whip out your magic notebook and put your money where your mouth is.
Those people are the ones I remember and are far more likely to get a letter saying "Hey, I've got a hole and I think you can fill it. Wanna give it a try?" than someone who tells me "I have this great idea" but doesn't do the work of writing it out before comming to me. Even an unpublished writer can (and should) build a portfolio.
Absolutely. I had 3 years professional experience and a degree in writing and I had to start small, first with my own publication, and then with a publisher. I took low pay and tough assignments to start building a name for myself. It seems you want to start your own company straight out - personally, I would advise against it. The market is glutted with new publishers, and there is, admittedly, a lot of crap being produced. Guys like Monte Cook are able to start a company and succeed because they have a name, the experience to know what would sell and are experienced in the craft (which Wil and Will have alluded to above).
Another thing to consider is that there are going to be days, weeks, and sometimes months were its not fun - its work...If you don't plan to love it, honestly, don't even start. You can still save yourself

.
Back in college, my mentor talked about writing as craft, and ONLY as craft. It was really hard to understand that back then. Now, my day job is a copywriter, and now my moonlighting job is an RPG writer, and it's taught me just how much craft there is in the business. By day, I grind out advertising and web copy - creativity on demand - and by night, I grind out rules copy - creativity by necessity. Some days I can write/sit in front of a computer for 16 hours a day, with only an hour or two for eating and commute in between. I only eat because of my day job, and my night job doesn't pay well, is more demanding than I could have expected going in (tight deadlines, tough creative challenges, far more skillsets at work at once), and yet i do it for the creative satisfaction alone. Craft is the discipline to do the work each day - but love for the work is what fuels the discipline.
Good luck and best wishes,
Alex