I wouldn't worry about the time thing. I planned on writing for a year but I was done and put it in the mail today and I started writing on Oct 5th. I just kept simplifying and elaborating on main points and beating certain ideas to death. It's a weird feeling once I had 2 chapters done, the rest sort of came as if it were a conversation. Once I got going I prefered writing to watching TV or anything else I used to do to inwind at the end of the day. Don't congrate me yet, I'm in the hard stage now which is getting your first book ever published. It may take years and 100's of submissions. No matter what happens I have a backup plan of self publishing thru Vantage press.
Reading for core concepts sure made it easier to write. I'll tell you one thing and EVERYONE LISTEN UP!!!!!!!!! If there are books out there like RichDad/Poor Dad and Who moved My cheese that became best sellers we all could do it.