Any good tips or tools for expired domains?

I have been looking at buying a few expired domains with good seed sites. I'm new in this area as I do mostly ptc or cpm. It seems to be a lot of work, but it seems it could pay off if I find a few gems.

I'm using expireddomains.net to do my digging........

I look at the backlinks for seed sites. is this correct? and if so. are there any tools you recomend.

I'm new at the expired domain area, but I can see how it could very much help at what I have been doing.

Some tips would be cool. Not looking to be spoon feed. I need to learn myself.