Here are the best sites and forums of Dnowledge...
These sites have the best free forums to get a human response to your questions and there is some overlap, which is a good thing...
www.russianiron.com -a little bit of all makes.
http://autos.groups.yahoo.com/group/dneprheads/ -Dneprs only.
http://groups.msn.com/bCozz -Old stuff of all makes. Pack a lunch. You'll be here a few minutes.
http://autos.groups.yahoo.com/group/wagnerscycle/ -New Urals. They are a dealership, but some of the most helpful overall if your dealer comes up lacking.
http://www.sheldonaubut.com/narma/narma/brands/ural.htm -a copy of an old, now defunct site that still has some good things on it.
http://www.cossackownersclub.co.uk/spec_sheets_urals_&_kmz.pdf -a chart of all the when, where, what, how big, etc. for most all models. After you check that out, delete everything after the last "/" and visit their home page and check out the library.
http://mymotostuff.tripod.com/motorcycles_uraldnepr.html -tech manuals galore (BTW, There are no FREE K-750 manuals on the web anywhere in any language, so don't drive yourself crazy.)
http://www.molotovmotors.com/history.html -a good history and the site where you buy the mega-bible of Russian bike knowledge. It's nice to have as a reference on all Ruskie bikes and simples maintenance and mods, but it's not a Chiltons.
Kit bikes, restorations, and other works in progress...
http://www.ferraraworld.com/dnepr_chron_main.htm -the ongoing saga of a man and his motorcycle "kit" with lot of photos. I highly recommend this site for anyone considering a kit bike. (Go to his homepage and check out his "Downloads" section)
http://www.gummiente.ca -the NON-going saga of a man and his Dnepr that got sold to finance his 2005 Ural that he's now having a blast on.
http://www.curtperedina.com/dnepr.html -another satisfied Dnepr masochist orders "the kit". Lots of praises for Yuri's service.
http://web.telia.com/~u60530575/k750/kmz.html -photos of a K-750 in various stages of restoration.
www.russian-spares.com -Dave in Russia says he can sometimes get you stuff before your dealer can.
www.uralmaster.com -Oleg in Russia seems to be a straight forward guy that can get almost anything, too.
www.theborgenterprises.com -Steve Borg's parts and tools galore for Dneprs.
Adventures in Russian reliability...
http://www.realclassic.co.uk/ridesfiles/rides05060700.html -two guys on two second hand Ruskie bikes trying to drive across Europe
http://www.realclassic.co.uk/ridesfiles/rides05061000.html -part 2
http://www.realclassic.co.uk/ridesfiles/rides05061700.html -part 3
http://www.redmotorz.studioo.pl/galeria/index.htm -photos of classic Russian rigs driven to the limit.
http://www.redmotorz.studioo.pl/html/filmy.htm - films of classic Russian rigs driven to the limit.
Importing your own...
I haven't tried it yet, but the bike must be pre-1978 to meet EPA exclusions (a 21 year old vehicle can qualify for an exemption, though, with a little more paperwork) and at least 25 years old to meet DOT safety exemptions. So, I wouldn't attempt anything made after 1977 (though possible up to 1980-81 with some extra paperwork). Some have done it successfully with newer bikes only to get grief when they try to register them with their state DMV. Others had to pay to get their bikes crushed! Be wary, especially of the Chang-Jiangs as they ALL are listed as 1957 models and I'm sure the customs guys are onto this by now.
http://www.epa.gov/otaq/imports/factmnb.htm -the pertinent part of the EPA regulation.
http://www.epa.gov/otaq/imports/forms/3520-1.pdf -the EPA form.
http://www.nhtsa.dot.gov/cars/rules/import/FAQ%20Site/pages/page2.html#Anchor-28852 -the pertinent part of the DOT regulation.
http://www.nhtsa.dot.gov/cars/rules/import/hs799short.pdf -the DOT form.
General motorcycle/sidecar stuff...
http://www.dansmc.com/MC_repaircourse.htm -a great all around generic repair resource.
http://www.sidecar.com/links3.asp -more than you ever want to know about driving a rig. Watch out for those right handers!
German WWII sidecars...
www.wehrmachtsgespann.de -the Holy Grail of sidecars. The Zundapp KS-750 and the BMW R-75 were no punches pulled, no expenses spared, dual range, 10 gear, 2WD German war machines.