So I'm being sued, how do I proceed?

Okay, here's the situation. I went by a friend's place the other day to drop something off, and he said someone had come by earlier that morning looking for me to give a summons to court. I previously lived with this guy so obviously they have my old address. My friend told them he didn't know who I was and the guy left without leaving any paperwork or anything behind.

Now, just yesterday I got a letter forwarded from my old address by the post office from a local lawyer saying that according to county records there has been a law suit filed against me, offering to represent me.

Where do I stand now? If they don't serve me the papers, what happens? I don't even know who it is thats suing me. Should I be calling the county, or should I be looking for a lawyer, or what? Preferably I would like to speak with the creditor before any judgements are filed. I have a few credit cards that have defaulted and I assume that is the source of this, however I came into some money recently and was looking into settling/cleaning up my credit report anyway.

I'm wary of calling any lawyers as I don't trust any of them. Any direction here is appreciated very much.

Thanks!