I just spent a few days overhauling my aging mountain bike. It was an interesting (and at times frustrating) process, partly due to this being the first time I’ve done anything like it, and partly due to the apparent lack of maintenance manuals for the bike or many of its components. I thought it might be useful to put together a brief Marin Bobcat Trail maintenance manual, in the hope it’s useful to someone else who owns the 2008 or 2009 edition of the bike. I’m new to this, so it’s probably a laughable effort in cycling circles, but it’ll be useful to me next time I overhaul the bike anyway. Feedback welcome at the address given in the document!
The Haynes Bike Book was a bit of a bible for this kind of thing. For any Shimano parts you can get both assembly instructions and service guides with nice exploded diagrams for everything they have ever made from techdocs.shimano.com. Looking at your (nice) diagrams even if the Marin has generic components, the design is the same as Shimano. You don't need to record the exact cable outer lengths - the stock outers are usually generously proportioned (for ease of assembly, not optimal braking/shifting) anyway. I'd use blue loctite on remounting the brake studs in the frame, you don't want those coming loose. And I guess you've already found sheldonbrown.com... Sounds like you had fun doing this and learned a lot, keep it up!
I'll repeat the endorsements for sheldonbrown.com and techdocs.shimano.com. Also, the Park Big Blue Book is pretty good for general maintenance.
One tip I've seen for dismantling hubs is to string the parts onto a cable tie as they come off, so you can put them back on again in the right order. I may have spend two hours putting a hub back together because I managed to knock the tray holding the pieces.
Thanks (both of you!) for the helpful responses. I’ve used both Sheldon Brown’s site and techdocs.shimano.com (which was invaluable when re-adjusting the rear derailleur). I’ll have to take a look at the books you recommend.
Unfortunately I couldn’t use the cable tie trick for the rear hub, as the balls were loose rather than in cages, and the rest of the rear hub was trivial to reassemble. Oh well.