The most important advice I can give is not to waste your time on slipping or watching TV/movies but build your first product to sell.
Some people after quiting theirs day jobs think that they should get a kind of vacation and return after that with a new power. However this 'vacation' may continue over years. And I do not speak about active vacations when you travel or doing something to have a rest. I mean that you sleep untill 1 or 2 pm, then you browse the Internet for news and new blog posts, checking your emails and spending your time to imitate ebullient activity.
Good luck with your startup!
I think the most important rule, from my experience, is to pick competent and dedicated partners.
Make certain everyone has the same vision regarding the direction we are going.
When you get some money, be very frugal about how you spend it. If you don't need an office downtown, get something less expensive.
And finally, be able to explain clearly and concisely what you are doing and why it is different than your competitors.
You should also read How to make friends and influence people as that book is about sales, and you will be selling yourself and an idea, in the beginning, and the book just has fantastic advice.
Here are a couple others that are interesting:
4 rule for the practical entrepreneur
http://www.userscape.com/blog/index.php/site/comments/4_rules_for_the_practical_entrepreneur 3 rules for the new small business entrepreneur
Buy time. Pay ahead.
If you can afford it, pay bills ahead a few months in advance. Small bills like electric, cable, phone and cell. A $30 bill may not seem like much now but when things get a little tight (and they will), knowing you have lights for a couple more months will be one less thing you have to worry about. One month is good, three months is better, six months is great.
And before anyone comments on the time cost of money, (banking the money and collecting interest), this advice is for her peace of mind. Time and some calm is worth more than the small interest rate she might earn.
Don't expect to become a big hit overnight. Great products take years to build and mature. Dig in for the long haul and try to make small improvements every single day.
Expect your first few projects to fail. Give them your all, but don't take it personally when they don't work out. It's something everyone goes through, and the sooner you get it out of the way the better your odds of finding the right thing are.
A few things that I took away from the book "Founders at Work" were:
Forgot earlier - check out this thread, pearls of wisdom for entrepreneurs:
Always always always think about how you can turn one of your everyday activities into something lucrative. We have so many resources today that help us facilitate this process -- eBay, Amazon, craigslist...
All good advice above. The one thing I'll say is LOVE what you do - love what you're selling. It makes all the difference in the world. Doesn't mean you can't succeed without that but there's nothing better than having that. Because it's about the journey, not just the end point you're trying to hit. And if you love what you do then each day along the way you'll be better. And if you don't enjoy the journey then it's going to be sad if you don't hit your goals.
Best of luck!
networking, another important aspect
Think about the following: