Updated information on woodblock printmaking
First: there is an oil based ink made from soy that is non-toxic and easy to work and clean up.
T.N. Lawrence and a London based printmaking supply company both sell Akua inks. This is wonderful ink with terrific colours in addition to the blacks.
Second: buy the best carving tools that you can afford and keep them sharp. A dull blade will cause all kinds of carving problems.
Third, instead of buying great hunks of wood at enormous costs, think about buying a decent plywood (1/2" at least to minimize warping).
I like to use poplar but ask your local lumber supplier for advice. Soft wood is easier to carve but harder wood gives a finer line.
Fourth: use the thin Japanese papers for the best results. Ask for sumi-e (ink painting) paper. One can buy it in rolls or sheets.
Fifth: instead of covering a book with a towel and risking the wood moving, use a bench hook. Cheap to buy and cheaper to make you own. Essentially it is three pieces of wood screwed together. Google the word or just ask at your local art store. Check the image.
Sixth: have fun but be aware that this art form can be habit forming.