Asking for foreclosure listings is a pretty broad request. If you're asking about getting the information for properties that are in the pre-foreclosure stage (before the actual auction), you can access this information for free at the county recorder's office, but that process takes considerable time and effort.
Title companies will often gather this information and pass it along to potential clients in hopes of gaining future business; however, I've found this information to be incomplete and dated.
Of course you can pay for the same information, but most of the services that I've tried aren't much better than what the title companies offer for free.
If the property goes to auction and no one buys it, ownership goes back to the lender who will then list it on the MLS as an REO. If you're interested in REOs, I have a saved property search that I created on our MLS and I'd be happy to add you to the notification list.
The real question though is, why foreclosures? Many times when a potential client inquires about foreclosures, we find that they really aren't interested in foreclosures, but rather finding a good deal. We do keep a watchful eye on pre-foreclosures & REOs, but it's part of a larger net that we cast when looking for good deals for our clients.