Learning cross-browser development (CSS/XHTML)

I have been out开发者_运维问答 of the loop with web development for about a year and a half now. My current project is working/functioning well with OS X browsers; Google Chrome, Apple Safari and Mozilla Firefox (minus a few things).

Many things have changed since I was working heavily with these technologies. Does anyone have any suggestions in the right direction towards multiple browser support, (Windows platform)?

Are there any new markup/style-sheet statements I need to learn, what's the best way to go about multi-browser support these days?

I understand not everything needs to look the same in every browser, but I just need a kick-start so to speak.

Thanks.

I already said this in the comments, but since no one has posted an answer... :)

Sadly, nothing's really changed in the web design world--it still consists of getting the damn thing to work in IE. It's a lot better if you don't have to support IE6, but it's still the same old trial-and-error process. No one has, as of yet, introduced some magical framework to make these issues go away.

The only possible difference now is that there's a lot more reading and documentation on specific issues, so if you run into a problem with CSS, chances are someone's written about it.