In November 2008 I had that same surgery on my right hand (really, I need both hands done, but I'm left hand dominant and wanted to do it on my non-dominant hand first and also because it was worse).
Anywho- the recovery took a while. Luckily I had all winter to recover and work on getting back. Riding the bike took a good couple months to be able to put the slightest pressure at all on the handlebars. About 4 months out I was able to ride for short periods (and hour or so) with little pain. By about 7 months out I was pretty much back to normal. I have a tri bike, tho, and was lucky that I could lay down and give that hand some rest as needed. It took me longer to get back to riding my upright commuter bike normally again (I didn't have a regular road bike at the time).
It was about 6 months before I could do a "girl" push up, and even two years later, I have trouble doing more than about 5 full pushups without a rest for that hand.
I massaged the scar area daily, but not as faithfully as I should have. There will always be scar tissue there, but if I had massaged it multiple times a day like it was suggested I'm certain it would have healed faster and minimized the amount of scar tissue that accumulated.
When is your surgery?
The best part is learning how to pull up your pants and get dressed one handed. I had to ask a co-worker to button my pants one time because I couldn't do it (about 5 days after surgery- that was not my finest moment). I'm sure I was quite the sight.