As far as fertilization goes differently want to use starter fertilizer for new grass however you don't want to use any fertilizer until new grass is up and have been mowed a couple of times. New grass is very susceptible to being burned by fertilizer. You should check your soil now and and lime or anything else it needs, you could even fertilize about a month before you plan unseating to have nutrients in the soil if you want.
Whether you need to remove thatch or not depends on the condition of your lawn. You don't want it all removed because it will actually help the ground hold moisture to help termination of the new seeds.
Written using Dragon Naturally Speaking