The wood typically used in the traditional Japanese method is the yamazakura (mountain cherry). It is very hard - hard enough to allow thousands of copies of the print to be made from it, even when very delicate lines are part of the design. With your first print though, thousands of copies is probably not what you have in mind, so a material somewhat easier to carve is preferable. Here are some pros and cons of a few common options, at least one of which should be obtainable somewhere near you.

Wood types:

• Birch plywood (or any plywood made with a similar hardwood). Birch ply is the material of choice for most of the thousands of woodblock printmakers in Japan today. They have no need of the delicacy of the cherry wood - what they are looking for is ease of carving, and enough 'body' in the wood to allow deep smooth colour to be printed. Most softwood plywoods do not have a smooth and firm enough surface to print well, but a good hardwood plywood has just the right characteristics. Birch ply is a little more expensive than softwood ply, and you may have to phone around a bit to find some, but it is far and away the best recommendation for the beginner.
• 'White' woods such as poplar and basswood. Moving from the ply to a 'solid' wood brings both benefits and problems. These woods are easily available absolutely everywhere, and any local woodyard can slice a piece for you in whatever size you want, and then run it through their planer to make it smooth enough for carving. These woods carve easily, and take decent impressions. In the 'negative' column is their propensity for warping - a problem that you won't encounter with the plywood. In a small-scale print like our sample design, this probably won't be a major problem, but if you are attempting larger works, block warping can really cause problems ...
• 'Evergreen' woods such as pine and fir. These are really not recommended for your first tries at woodblock printmaking. Although they are soft, and thus cut easily, they have one particular characteristic that makes them difficult to use, both in cutting and printing - their grain is very pronounced, with the dark 'winter' wood being very much harder than the light coloured 'summer' wood. This gives a lot of trouble with the carving knife as it 'jumps' across the grain lines, and of course when you are printing, such pronounced grain easily shows up in the print (this of course may be exactly what you want sometimes, so is not always a 'negative' point).
• Hardwoods such as walnut and maple. Although sometimes chosen by printmakers, usually because of their ready availability, such woods offer no real benefit over the traditional cherry wood. The 'pores' in cherry (those extremely small 'tubes' through which the sap and water flowed when the tree was alive) are very small, and the colour can thus be applied to the print in a smooth sheet, but most other hardwoods have larger pores, and these can leave 'speckled' patterns in the colour.
• Tropical hardwoods are not suitable for water-based printmaking at all, as they are so hard and dense that the pigment will not be absorbed at all into their surface, and you will get nothing but a splotchy mess ...

So does that leave you with some ideas on what wood will be best for your first experiments?

Size:

Whichever wood you choose, have the woodyard cut it to a size just a bit larger than the print you plan to make. In the case of our example print, which has an image area of 6 1/2" x 7 1/2", we will first need to add 1/2" to each dimension to allow for a white border around the image. Then, extra space will be needed to cut the registration marks - say another 1/2" in both dimensions. So the minimum size for a woodblock for this print will be 7 1/2" wide by 8 1/2" long. (The woodgrain should run in the 'long' dimension.)

We will need five pieces of wood for the print, one for the key block, and four for colour blocks. (There are actually six colours in the print (not counting the black key block), but we will be able to put more than one colour on a block in a couple of cases.)

Another way to save wood is to use both sides of the block, but this is only practical if the wood is reasonably thick to start with. If using plywood, it should be at least 1/2" thick for this, and solid blocks should be around 3/4" thick. If you wish to do this for our sample print, you will thus need only three pieces of wood - one for the key block, and two for the colour blocks (using both sides).

The wood will need no special treatment before we use it - no varnishing or other sealing is necessary. All it needs to be is smooth and clean ...

Once you've got your wood ready, it's time to paste down the tracing and begin carving ...