Hi, do you guys have parked domains? If so, how much on average you make? Is it worth it? What are the options (services) available? Thanks.

I'd start with Sedo or NameDrive if I were you. Unless you've got some killer domains, you're not going to get rich off DN parking. The idea is to build a powerful portfolio or to buy good domains from others. When you're starting out, you'll probably buy a lot of duds until you figure out how to evaluate a good domain. Unless of course you want to buy a domain with proven traffic potential from someone else.

Yes, it is quite difficult to profit from an average domain from parking. You can try out NameDrive for sometime and experience yourself. I would concentrate on developing it to into a mini-site at least to capture Search Engine traffic.