Walnut stain is good for scratches on dark furniture, kitchen counters and wood floors but simple walnuts can do the trick very nicely for a while too. Coffee grounds work too, I think.

Screwdrivers, pliers, hammers, power drills and scissors which can cut all kinds of materials (they look a bit like garden clippers) are your friends. Put them where you can easily access them and learn how to use them if you don't.

If you're like me and can't remember how to start/stop stopcocks or valves (is it clockwise or counterclockwise?), make a drawing or write instructions on a piece of paper and stick it on your fridge.