Starting up my own company was my dream since my college days but I worked at Tata Consultancy Services Ltd. as a SAP ABAP Developer for 2 years after completing my graduation. It was a nice job with smart people around me and interesting work to do, not to forget the high salary SAP consultants get. It was good for 2 years but then I felt my job was dragging me away from my dream. The whole corporate environment started to suck. It was time to leave the shores and get into the deep sea.
I had some good ideas related to web. My plan was to work together with two of my college friends and they both agreed on this thing. I never asked them to quit their jobs but to just work on weekends. One of them backed out at last moment.
Lesson learned - Don't make your plans dependent on others. Make sure you alone can handle it if required.
Its getting long so I will just point out other suggestions I have for you:
1. Have a fail back strategy for everything.
2. Get a co-founder but make sure he is as committed to your idea as you are. Some of them will try to tell you how you need to do something else to get some quick money and then use that for your project. Those people are interested in earning money and not in your idea.
3. Spend as little cash as possible.
4. Focus on only one project - your dream project - as early as possible. Don't waste your time on random projects for learning or to earn quick cash.
5. Choose a technology platform early and stick with it.
6. Release your Version 1.0 as early as possible.
7. Don't work 24/7/365. Its not good in long run. Give 8-12 hours per day and take a day off on Sundays. Important thing is to be consistent.
8. Network with people who can help you - other hackers, designer, entrepreneurs, etc. Use your weekends for this.
9. Stay away from your friends or family members who discourage you. Stay away from their negative energy. However you positive or sure you may be it will affect you. Good thing will be to have a limited contact with such people.
10. Don't get involved in love relationships unless your girlfriend is supportive.
Best of luck.