I like it and I can see you put a lot of work into this guide. I too play jungle Rammus and I also have a guide on mobafire that I think you should look at to see how you have improve http://www.mobafire.com/league-of-legends/build/whats-an-armadillo-doing-in-my-jungle-updated-again-30503. (Hope this doesn't violate the rules by linking this, I'm not trying to advertise but just help my Rammus friend out. Hope it's ok)

Anyways. There are a few minor details I would like to point out.

First off for the items. I prefer getting sunfire cape first because it really helps with farming/jungling.

Second. For the masteries I like getting improved buff duration because there are some mastery points that aren't really needed like Ardor so I like to go 1-19-10. Again just my preference.

Lastly. The skill order is a bit off IMO. Taunt is a lot more valuable to have maxed first because it really helps out in ganking and the increase to W when ranking up isn't that crucial.

Other than that everything else is good! +1