Tuxfan, by SSI I meant using apache Server Side Includes which can be used in shtml pages.
You can also use PHP includes the effect will be same.
About CSS, actually you wont find books in India but on Amazon they have good colleciton of books...
Book Web Standards Solution is a good book to understand web standards and basic CSS..
I have written review on it, if you want then you can check it out
here, there is one more good book for CSS called Zen of CSS but it is more of case studies and it is for the guys who know CSS well...
You can also checkout some articles on
Sitepoint, they have good collection of articles on CSS, you can also check out sites like
CSS Zen Garden (check out their resources section too)
For asking css doubts in forums, Sitepoint forums is the best place, full of CSS experts...
I hope this helps you.
Regards
Deep