Easy, and like another poster stated, machine rental is free with purchase of a relatively small amount of material, so MUCH cheaper than paying to have it done.
Cellulose is going to be cheaper and wont irritate your skin like fiberglass, but it is dusty and will haze up the area you are blowing the insulation in, and possibly seep through any cracks, so some cleaning up may be needed.
Blown in fiberglass is the same stuff that's been used for years, just in a different form. Not very dusty, but is makes some most people itch like crazy.
Cellulose, being cheaper, and having better r-value for a given thickness, buy it cheap, pack it deep.
As far as blowing it in, the place you get insulation at might have some plastic rules you can tack onto the joists so you can gauge how much your piling up. Wear a respirator, the air gets a bit thick after a while.