As you don't actually tell us what you use your current server from we can't really say.
There's a big difference if you're using it as an AD server with File Sharing and user authentication / permissions, VSS versioning, user provisioned reverting etc.
If you're using it as a web server for static HTML pages then there's nothing frightening.
If it's PHP then you'll need to check for anything that has paths as you'll not have C:\ etc.
So decide what you're actually asking
The secret to any migration is to TEST, TEST, TEST!