mjl5007, You have the deck stacked against you,as far as spring seeding goes. Aggressive summer annuals that are hard to kill compete against your grasses, soon to be hot weather, disease, traffic ( this is when you want to be enjoying your yard), and a shallow root system from your newly seeded grass. So no, I would not seed anything now. Get a few pieces of sod if you have larger bare areas, it will stand a better chance. Thinner areas will fill in be patient warmer temps, longer days and a little fert. will go a long way. Yes, if you need to regrade large areas get some fill dirt and use a good screened topsoil for the top 3 to 4 inches. The screened topsoil will keep most of the troublesome perennial weeds out of your lawn. I would say to hold off on the aerifying because you said your lawn is thin in areas, and I would not want to thin it out even more. Also, without any pictures it's hard to say, but light, moisture, and nutrients are more limiting factors to turfgrass growth than compaction. Unless you guys play a lot of sports on your lawn, then I would say yes aerify. When you aerify you need to go over the lawn four or five times to affect any real surface area. You will also need to aerify in the fall before you seed. The reason for aerifying when you put out lime is that lime moves very slowly in the soil, so your raising the pH in the soil in the top 2 or 3 inches instead of just the top inch.

Lisa....No, you would absolutely not be foolish to try to seed your lawn yourselves. Pictures always help people on here & I'm sure would improve the quality of advice you receive. If at all possible try to post a couple. The two biggest factors to consider in doing it yourself are the time & effort it will take. It sounds like the landscapers you've talked to are trying to make money off you, especially the guy who says it needs 7" of topsoil (no freakin' way). I guarantee you, if you just left it the way it is now some type of grass is going to grow on it's own. The first step is to get the surface as smooth as possible (i.e. no big rocks to run over with your mower). Many options here from physically raking the area yourself (tedious, back breaking work) to hiring someone to "prep" it for you the way you want it. Second thing is to get a soil sample taken of the dirt in your yard. Your county extension office is a good source for this. This will let you know what needs to be added to the soil in order to grow the type of grass you want (probably either Fescue or Bluegrass where you are). Equipment you'll need include a decent rotary spreader for sowing seed & applying fertilizers, enough water hose to be able to get the entire area wet & obviously a mower if you don't have one already. I could keep going but my answer to your basic question is yes, you can do it yourself....Good luck.

Morpheuspa mentioned water hammer being a problem for him with the Orbit unit, it was for me too. I have pretty bad water hammer already from my washing machine, but it was a bit worse with the sprinkler valves. So I found a couple of cheap (12 bucks) Oatey "Quiet Pipes" arrestors and a pair of caps to close them off, and just attached them to the two unused valves on my manifold, opened those valves, and water hammer is totally gone. Maybe one would be fine and two are not needed, but I bought two so that I can reinstall them on my washing machine permanently when I take the sprinklers down. Makes me feel better about leaving the house with the timer on, just thought I'd mention this cheap fix in case someone else out there has scary water hammer like mine.

Moved into new construction and in about a month or so, landscaper will be installing seed, etc to establish the lawn. Can't afford a proper irrigation system, so am setting up hoses to various sprinklers (tripods, oscillators, etc) to cover various zones. I'm researching hose end timers (I have two exterior bibs - one on each side of the house). I need a total of 7 hoses to cover the lawn - 4 originating on one side of the house, 3 on the other. All the 3 or 4 port hose end timers reviews are pretty mixed/negative. Best so far I've seen of the bunch seem to be either melnor 53280 or 558-219 or the orbit 58911. Seems though the single, 1 port hose end timers get the best reviews - My question is can i use 3 or 4 separate one port hose timers all on the same hose bib? and if so, how? Please dumb it down as this is all new to me. Thank you!