Hi Vijay,
get urself 1st page software from -
http://www.evrsoft.com/1stpage/ It's free, moreover it has good HTML, CSS referece and many more JavaScripts, DHTML efeects including rollovers and much more. The product is too good to be free.
Also, coming back to ur original Q, yes CSS is supported in most 4+ browsers. Moreover new generation browsers support CSS2 as specified by w3c.
You can have a look at
this for few more resources and JavaScript, DHTML tips.
HTH,
- Manish
p.s. I am *not* associated with 1st page in any way, and they are not paying me to say this
