That does not mean that you can't sync your address book contacts. You can do so if you want to. The message is telling you that it isn't necessary - its not saying that you can't.
You don't need to be running Lion to use some of the features of iCloud anyway. I was using iCloud for some things with Snow Leopard like you are running.
This is an example of how you can sync content with iTunes. In this example, it shows how to sync music. But this works the same way with all content in all of the different tabs in iTunes.
Connect the iPad to the Mac and launch iTunes.
Click on the iPad name on the left side under devices.
Click on the Music Tab on the right.
Click on all of the albums or playlists that you want to sync - or the entire library if you like.
Click on the Sync Music Heading.
Click on Apply in the lower right corner of iTunes
These might provide some help to you with syncing.