Adjusting Brakes and Gears on Bicycle

This applies to my blue bicycle.

Brakes

Release Bowden cable clamp, push brakes together until they are each 1mm from rim, then tighten the clamp again.

Notice the two screws on each side of the break. These adjust the symmetry in open position. If you tighten one screw, the open breaks will shift towards that screw. Pull and release the breaks repeatedly while adjusting these screws. I think they work best if you feel a bit of resistance in both screws.

Gears

You have a Shimano Deore transmission.

Flip the bike onto its seat and handlebar. On the rear derailleur you'll see three screws: Two right next to each other (let's call them "twins"), and a bigger screw close to the hub. You won't need this bigger screw, it's for adjusting the distance between the "eye" and the cogset when the chain is on the smallest sprocket.

None of your standard screwdrivers fit the heads of those screws, so you'll have to dig into your supply of bits. Take a medium-wide but thin, flat screwdriver.

Shift the chain onto the middle front sprocket and the smallest back sprocket.

Release the clamp on the the Bowden cable.

Turn the inside "twin" such that the derailleur is sits right above the smalles sprocket. Turning the screw in moves the derailleur towards the hub. On my bike, this screw must be turned out almost all the way. (In a mechanical sense. The screw is still almost all the way in, just turning it out further doesn't do anything.)

Make sure you can turn the fine-adjust on the end of the Bowden cable at least a few notches in each direction.

Pull the end of the Bowden cable with moderate force and clamp it.

Shift into 6th gear (the next bigger sprocket). If it doesn't go up there, increase the Bowden tension by turning the fine-adjust screw out by a few notches. Shift back into 7th. It should go back smoothly, otherwise release some thension in the cable and try with a different adjustment of the inside twin.

Note: Problems on shifting "down" are somewhat expected due to shoddy, dirty, unmaintained bowden cables. If it gets too bad, bite the bullet and clean the bowden cables, or buy new ones.

Shift into first gear on the back cogset. Adjust the outside twin such that the derailleur sits above that sprocket. I think turning it out moves it towards the hub. Careful: If you turn it out too much, the chain will fall between cogset and hub, if you turn in too much, you won't be able to shift into this gear. Some guy on the internet (TM) suggested to turn it in until you feel resistance, then back out by a quarter turn. That might also be good advice.

Shift around and play with the cable tension. Shifting down might not work very well due to shoddy bowden cables. Either buy new ones or live with that.