We have a 2-speed ceiling fan, but could only find a 3-speed pull switch to replace the old one. Will this work on our 2-speed fan? Anything specific I need to know? I've never done any electrical wiring so any help you can offer, I will certainly appreciate.

Depends on the 3 speed switch. If it's L-1-2-3 it will be fine, just don't use #2.

Two speed switches are available at any hardware store.