Re-posted from Springtime, but late-summer/early fall is the best time for lawn repair in most of the USA. We are refreshing one of our raggedy lawns, next week, with power-seeding with a tough sports turf seed (tough enough for the dogs and kids and occasionally the horses), and doing the aerating at the same time. Then Milorganite. By Spring, it will be perfect and crowd out the weeds. You can rent a power-seeder and an aerator for a few hours very cheaply, anywhere.
I will spare our readers my usual springtime lawn-restoring post, and bring a new topic to your attention: Power Lawn Seeding. This machine injects grass seed to a proper depth in an existing lawn or a new lawn. It's overseeding, but with far more effectiveness than surface scattering.
It will quickly give you a new or refurbished lawn, and sort-of aerates it in the process but best to arerate at the same time. We happen to need about 1/2 acre done this way due to stream flooding in a storm last fall. Services like Lawn Doctor can do it, or you can rent the machine for cheap and do it yourself.
Naturally, you have to either pray for rain or water it regularly for a few weeks.
Re lawn fertilizing (which must be done 2-3X/year), I enjoyed the credentials of the person who wrote up this piece: Dawn West holds a B.A. in English from Harvard University and teaches writing at Oregon State University.