Manuals are available at the Ruger website. However, if you've never taken this pistol apart before, I would very strongly suggest you take it a gunsmith and have them show you how to disassemble and reassemble it. Many people find the Ruger Mk. I, II, and III pistols a bit complicated, and the best way to learn is to actually be there, hands on, with someone who knows how.
You can get a manual for free at Ruger's web site.
You can request a owner's manual at the Ruger website.
Go to the Ruger website. There is a section to date your 22 by serial number.
Is it a revolver or semi-auto? You can go to Ruger's website to look up the serial number.
Ruger has sn data on their web site. 100-375 USD
100-400 or so
300 or so
very little market for ruger auto pistols, i would estimate 320 dollars or so depending on condition
10-200 USD or so
100-200
Depending on condition, around $125.
Depending on condition, 50-175 USD.