Aeration is very important, as is getting down a good fertilizer that will help in the spring. Too much, however, will burn the grass out now.
For weeds it really depends on the problem plant itself. For my house I've got a ton of "pricker plants" - don't know the actual name for em but the seeds blow in from the fields around us. I can hardly keep up with them in the back of the house, no matter how much weed killer i put down. Front is easier to control the damn things but they are terrible. I even tried using round-up this year and although it killed the weeds at first (and left a whole in the grass), the damn weeds have come back. The only thing that seems to work is the ortho product that kills weeds but doesn't kill the grass - except that you have to keep putting it on.
I've used a service for about 5 years now that comes about 4 times a year for us. It has helped control the crabgrass and most of the weeds but since they changed the formula 2 years ago due to too potent of weedkiller it hasn't controlled those damn prickers.
But yeah, make sure you get the lawn aerated by the middle of October.