How to start marketing?

Hi,

I have a couple of ideas for software products that I plan to pursue.

I plan to focus on what I think makes or breaks a business: marketing. In 
the software industry, people *hate* sales people and big company 
bull****. I know I do. Hence...

My questions: 
 * How/when do I start marketing these products? Before they are ready?
 * How can I gauge market interest before releasing?
 * If I have a beta program, how would I get people interested?
 * How do I not annoy the hell out of people and destroy my reputation 
   before it exists?

Please make up any questions you think I should have asked and answer 
them!

Thank you for your time.

-- 
Sohail Somani
http://uint32t.blogspot.com