I was one of the principals in a startup here in the Bay Area. The plan was that we would have enough sales to keep us afloat with only angel capital and no venture capital. Well they did not take my advice in spending what money we did have on sales and marketing, thus my hands were tied as the sales and marketing manager!! Stupid. I can't say the business has failed, but it sure has not gone anywhere yet as they are still waiting for more funding. So here are some pieces of advice froom my experience of what should be done:
1) Make sure there is some kind of check and balance system with the MONEY. If you fail to do this, someone somewhere will put a lot of entertainment expenses on the company's accout and it will suck you dry.
2) Someone has to be in charge. If it is you make sure you follow through with EVERYTHIING! If you are the least bit phlegmatic, get someone who is a choleric personality (a go getter/a driver) to manage and get done what needs to get done.
3) Be prepared to wear many hats....ALL OF THEM.
4) Be prepared to lose everything you invest, and then some. I took a realistic look at what I stodd to lose, and it came to be about FIVE TIMES HIGHER in terms of lost wages. At the end, my savings were drained, I was out of work in a down market (5.5 months), and I have lost about $50,000 in money I could have made outside of the startup. Live & learn.
5) Have some contingency plans for goodness sake. Without any, you can find yourself between a rock and a hardplace in short order. $$$$$$$$$....
6) Never apologize for going out on your own and doing your best, even if the business fails.
The advice given above in all the posts has been right on the money, period. If you decide to jump, jump in with both feet!!!! Don't look back either. I'm trying not to be negative, but just trying to be utterly realistic here.
Davy