Hey Greg, you might also want to check into one of these. I'm assuming that your generator is large enough to power your needs. The first is installed by your power company, http://www.generlink.com/about_generlink.cfm# Check on prices this might be much cheaper than a normal transfer switch.

This one requires you to know something about doing electrical work, http://www.marwellcorp.com/sp2376op.htm If you are not familiar with electrical panels don't use this one.

If you are only looking to add your water pump to your generator needs, have a plug and outlet installed for your water pump. When your power goes out unplug the pump and plug it into the generator. This might not be feasible depending on how your pump is wired and installed. HTH.