Congratulations on planning to pump! It's work but well worth it to continue doing the one great thing only Mama can do:) I did this with both mine until around 15 mos, but didn't need to pump from 12 mos to 15 mos.
Hopefully you have a double electric pump, and you'll need to pump around 3x a day, one morning, one lunch, one afternoon, if you're working full time, to keep your supply up during the day. If you don't pump, your body may not continue to produce when needed -- some women dry up from lack of steady, timed stimulation. Plan to try nursing once in morning and 2-3x in evening, depending on baby. Later, you can eliminate morning nursing for easier mornings:)
Don't worry about freezing the milk -- you'll never have a freezer full because your supply will vary as will your infant's needs. Some days are more voracious than others and then your body jumps to keep up.
And with all this, you will still probably need to supplement with formula, as I did with both (around 1 formula to 3 milk), despite pumping around 32 oz a day at my height of production. I guess both my kids were honkers:)
Good luck and be courageous -- only the brave make history:)