8x10 is fun, but the glass and film are much more expensive than with 4x5. I would recommend starting out at 4x5 which is a huge improvement over smaller formats.
One thing to watch for (I was surprised by this when I got my 8x10, although the mathematics is straightforward):
Although exposure (f-stop and shutter) are the same regardless of format, the depth of field at a given f-stop decreases with increasing format size. I was aghast when I repeated a 4x5 cityscape shot that I liked, using the 8x10, and did not close the lens down farther.