>I have succeeded in getting my site to number one on several different search engines but I am concerned that my techniques could lead the site to be penalized. I have two questions:
>1. Will the search engines contact me before they penalize the site (i.e. let me know I have to change things)? Does anyone know a good place to find this info out?
No, they definitely won't!
>2. What merits penalties for different search engines?
If you gave us your URL, we could judge your site a little more accurately. The two main things the search engines don't like are too many repetitions of keywords in the Meta keywords tag, or hidden text spammed with keywords (i.e. text that matches the background so only the SE spiders can see it).