Check out this site if you want to educate yourself a bit before meeting with the electrician:
http://www.selfhelpandmore.com/home-wiring-usa/
Note that this link applies to the 2002 version of the code. In 2005, the NEC significantly changed its requirements for pool bonding, both above ground and in-ground. Most everything else related to a pool though remained unchanged. You might want to contact your electrical inspector while in the planning stages to get his/her thoughts on how the pool bonding will be inspected. The 2005 NEC has much more stringent bonding requirements than most AG pools have employed. As time goes on, these rules will become both better understood, and therefore enforced more uniformly.
I agree with Jason - after all the rules are applied, you generally are forced into a dedicated circuit for your pump motor. My memory says this is more or less explicit in the pool rules of the NEC. And your electrician may suggest that you oversize your wiring to reduce voltage drop to the pump if you have a long run of wire. Trust him to provide good advice on that, or specifically ask him to calculate your resistance voltage drop for you as a percentage. Keep in mind that this percentage is essentially the percentage of electricity you are paying for that is used for heating your wires rather than powering your pump motor (i.e., it's wasted electrical power).
And while subpanels are nice, going bigger will cost more, so you shouldn't leave yourself too much extra room if you can't afford it.
I would suggest you consider going with only 20A circuits, even for general purpose/outlet circuits. You essentially get another third of a circuit with the cost difference being quite small.
The most cost effective way of wiring a modest AG pool with a 120V pump motor, in my opinion, is to run 2 20A circuits from your main breaker panel into a new box located near the main breaker panel. This box will hold two non-outlet GFI devices which will protect both circuits downstream of that point. Run one of these circuits to your pump motor using 12 or 10 AWG from the GFI output to the motor access point (twist lock receptacle??). Your timer can plug into this receptacle, then your pump motor into that timer. The other circuit provides general purpose service to the pool vicinity, and can in fact go to multiple outlets if you'd like that convenience. Alternatively, you can buy more expensive GFI breakers and eliminate the GFI devices and the stand-alone box near your main breaker panel. GFI breakers are typically pricey, but perhaps they've come down in price over the years???
The link above is good reading, if you're so inclined, and a brief chat with your inspector during the planning stage cannot hurt either.
Good luck!