700CX14GX36H means it's a:
- 700c rim (actually ISO 622mm diameter, as the Sheldon Brown page linked by Brad describes)
- taking 14 gauge spokes
- with 36 spoke holes
So, you need to know the
700c bit if you're buying tyres or tubes, you need to know the
14g bit if you're replacing spokes, and you need to know the
36H bit if you're re-lacing the rim to a new hub (which will need to have 36 spoke holes to match).
700c and 14 gauge spokes is standard for road bike wheels.
36 is a fairly high spoke count, meaning it should be durable and relatively easy to repair and re-true. On the other hand, lower spoke-count wheels may be lighter and more aerodynamic (at the possible cost of being more fragile and harder to repair).
Can someone provide an explanation of what general tire and tube size specifications mean?
700x23 means a tyre fitting a 700c rim, with approximate inflated cross-sectional diameter of 23mm.
700x32 is a fatter (32mm vs. 23mm) tyre for the same diameter rim. Note that even for the "correct" diameter, different tyres fit more or less easily on different rims.
A tube described as
700x18-23 would fit the first (
700x23) tyre, but would be likely to burst before filling the greater volume of the fatter
As for a general explanation ... Sheldon's table is probably the best you're going to get.