P411, Datecheck and RS2K.

They are the best way to break into the hobby when you have no references.

the fact that you were previously active is moot, unless you find someone from those days to vouch for you. Even then, many providers want current references. You have to do what any newbies do - use verification services like Mr. F mentioned; be prepared to give work info, which some providers will accept in lieu of references; and/or build a new set of references through indies or agencies who don't screen or screen very lightly (they do exist).

Step 2 find providers who see newbies and get them to verify you.

Step 3 get more verifications and then you are set.

Yes, it may take a couple weeks to do all of this but pretty soon you will have enough references for most anyones requirements.  If you do things the right way it should work well, if you don't have patience you wont get anywhere in hobbywood.