What to carry in an on the road imergency kit to keep going. Like What tools COULD YOU USE to fix and install a chain or fix a cable. This could be like a "particular Leatherman" in stead of all the right tools etc.

How to adjust a headset since they can come loose and It is not good for riding with a headset

What tools will be needed to maintain a bike.

Not to be a downer, but there are quite a few very excellent books and websites out there that have detailed instructions for bike repair. Park Tool (manufacturer of bike tools) web site is amazingly good.

http://www.parktool.com/blog/repair-help

Also, the books by Lennard Zinn are readily available, updated regularly, and are expertly written

http://www.amazon.com/Zinn-Art-Road-Bike...

I'd suggest that bike repair is sufficiently well-covered elsewhere online and in print, and your efforts would be better spent expaining repair of things that don't have such existing documentation.

One of the keys of bike repair is fixing the actual cause, not just something you suspect to be the problem. In other words, I would suggest a serious diagnostic section. (For example, if you're having a problem with the chain switching gears or falling off the front gear, you can waste a LOT of time adjusting your derailleurs when the actual problem might be a bent chain.) Such a diagnostic section should be full of the most common problems, average lifetimes of various components, as well as various ways to test what may be the actual problem.

I will admit to having a bias toward utility cycling, but these are the things I get asked about over and over and over as an amateur mechanic:

Cable Changing

different cables

headset bracket overhaul, adjustment

changing handgrips

attaching fenders

attaching rear rack

attaching basket

wheel maintenance (spokes, etc)

changing disk brake pads/adjustment

seat adjustment and swapping

I think that your mountain bike is a good example bike, but you might also consider a 10speed style and classic upright or comfort bike (path) ideally with an internally geared hub.

Tires are different and gearing is different and really, some of the brakes are different as well.

@velvetackbar

What about bespoke guides for the Brompton folding bike? (www.brompton.co.uk) I'm not sure how popular it is in the US (their website does show quite a lot of dealers there) but it is very popular here in London. Without wishing to sound silly, it really is the best fold up bike by far, folding down in a very clever way to a very small size.

The biggest problem is they are a little different to normal bikes to repair so good manuals would be great and I'm sure they'd be popular too!