Hi Bonne,

First of all, if you want to flash a different rom, you will have to root your phone. Please refer to this guide. It is the best guide in my opinion:
http://androidforums.com/wildfire-s-all-things-root/480954-guide-how-root-wildfire-s-s-finally.html
Once rooted, I suggest, Like Cafe has mentioned in the post, to first do a nandroid backup. If you ever run into a problem, you can always revert back to your "stock" rom.
There is a small guide at the end of the rooting procedure that really is pretty simple to use that will show you how to flash different roms.
As far as which roms to flash, I do like Cyanogen Mod a lot. But if you intent on flashing that, a lot of people don't realise at first is that CM does not support google apps (including play store). So along with the CM rom, there will be a file called gapps which will also have to be flashed just before you reboot the phone which will give you the google apps
If you go to to the forum XDA forums, you will find many many many roms to choose from. This forum doesn't really have any unfortunately.
My favorite Cyanogen version so far is CM 7.2. Although I believe there has been quite some progress on the CM 10. I am planning on trying that one once again in the next couple of days. Don't go for CM9 as it has been abandonned quite early in the day as CM10 came just a little while after CM9 was released.

Hope this helps!