I just purchased a complete dedicated 20" SS HBAR 22LR upper from Cheaper Than Dirt.
However, it does not include any instructions or maintenance manuals.
Are there any parts breakdown or service information available?
Any special break in procedures recommended?
Thanks !

I'ld say watch it and keep the chamber clean and lubed.  

As it gets dirty and chambering gets stiff you can have cases blow that aren't fully chambered and they can take out the extractor which means your kit is down.

Check your firing pin to make sure it doesn't contact the breech face under full travel and try not to dry fire it if at all possible.  [I peened the breech face on mine dry firing it twice [other than the once a magazine that happens when you run out of ammo] and that was another neccessitated repair.

DPMS has been promising documentation on the .22s for something like two years now. AFAIK no one has seen it yet.

I just bought the same one from Del-Ton over the weekend, though I have not had a chance to shoot mine yet. I do have the carbine version, and it has worked great since I sent it back to DPMS over the Summer. I think they redesigned part of the bolt carrier. The front of the original was black, while the replacement is bright bare metal. My new one is the same as the replacement.

What I have found is you need to keep the chamber clean, but that is about it.