I suggest beginning with YouTube. There are a great many short tutorial films on how to make various home repairs. Go there and search for the subject you need. For instance, I needed to replace an my ancient back porch light. I took a quick look at it and discovered that for this 1960s vintage house, nobody had bothered to put in an inset electricians box for the wiring and the guts of the light I'd purchased. What to do? Would I have to cut holes in the house and apply such a box ... something way beyond my knowledge base and any previous skill sets??? The answer was no. In one of the videos I discovered an exterior raised plate that both acts as the required box and brings the light vertical on the slightly canted surface of the exterior wall panel. That box cost only a few bucks and was quickly screw mounted to the wall, the electrical wire caulked in place, the new light's mechanisms housed comfortably in their new home, and the house improved in the process.
Amazing what you can do with the right video! Knowledge definitely is power.
Oh yes, and if the project requires working with tricky and potentially dangerous things you aren't comfortable with replacing (or anywhere near professional enough to do), call in an expert. Better safe than sorry ... or hospitalized! Just sayin'.
For my previous adventure in home maintenance, see: http://jsbrookspresents.blogspot.com/2013/01/secret-to-diy-small-project-success.html