To prevent rust, just keep on top of the cleaning, to kill rust if I have been lazy and not cleaned the bike, I use plain old vingar. Sometimes if the rust is being stubborn, I mix in lemon juice, then just wipe the residue away. For normal corrosion protection, I just spray the frame and associated bits with GT85, and let it dry, then alcohol wipe the braking surfaces and saddle.
My problem here though, is the sea air, my being tem minutes walk from the sea, anything rubber rots quickly and bare aluminium develops a white coating, so the spray oil is very necessary and cheap considering.
Tyres, the side walls they get regularly treated to black boot polish, it delays the decay, looks good and sheds mud easily. Just with a gloved finger massage the polish into your rubber and then wipe off and buff up the surface.