Same answer for you:

Apply a pre-m to perevent weed seed germination (use tupersan or tenacity if you want to overseed). Apply an N fertilizer monthly (starter fert can be used) as during the first year, a new lawn needs plenty of food. Water regularly when there is no rain. Spot spray any existing weeds with WBG or if you overseeded use Tenacity untill the germiated grass has been mowed a couple of times. Winerize at the end of the year and then use standard schedules for fertilization starting next year.

Thanks, grass1950! Based on the pictures that I posted, should I seed more this spring? I know KBG spreads, but it seems to me that my current coverage is severely lacking... Will the grass actually fill in a lot of the bare areas this spring?? (if properly watered and fertilized). I am not expecting full, lush coverage, I understand the "first year it sleeps, second year it creeps, and third year it leaps" adage, but I would at least want it to be more grass than dirt this summer...

Also, as far as watering, how much, how often?? If I do overseed, I would expect it to be the same as any other new seeding project, enough to keep the ground and seed constantly moist. If I don't have to overseed, then how much and often should I water??

Thanks again for the help, everyone!!

I wasn't able to pull the link up yesterday to you prior post with the pics. I saw it today. You need to re-seed those areas. You already know, that the best time is the end of summer. You could try annual rye this spring to help preven erosion and then re-seed at the end of the season with KBG or Re-seed with the KBG this spring. The rye may come in quick enough to avoid using blankets, but whenever you re-seed with the KBG, you're going to need blankets to hold the seed in place during KBG's extended germination. You've got your work cut out for you and it's going to be a challenge with those slopes.

Thanks for the response, grass, definitely not what I wanted to hear... Pretty much the entire yard is like this - about an acre of "grass" (1.3 acre lot, about 1 acre of "grass"). Spent over $700 on seed last fall, and the irrigation was a complete nightmare, between timers not working, sprinklers only covering about 1/4 the radius advertised, sprinkler heads freezing up, etc, etc. Most of the good germination came with the late fall rains that we had. I am really not looking forward to all of this all over again.

Erosion is most definitely a problem - it is even occurring underneath the snow. With some of the rains we had last week, some dirt was washed up onto the driveway, even though the entire yard is covered in a blanket of snow. I am not sure how the blankets would work - looks like it would cost about $3k for the size of my yard.

I have already spent about $8k on top soil, and grading the yard, which was well over the amount I had budgeted. A new round of seeding is already getting to be very expensive. I really want the cultivators I picked out and used last fall.

Could straw work?? That is what the people who did the top soil and grading suggested, but from reading other stuff on here and everything was under the impression that straw is optional, and an added expense that I could try and avoid...

This is really causing a lot of stress. I want this to turn out well, but am already well over-budget....

I remember your original post now that I've seen it, and at the time I purposely didn't respond as I considered it overwhelming.
You need to hold the topsoil you payed so dearly for. Sod is just too expensive and it's not like you just have a couple of slopes, the whole property is sloped.
You can use straw. I would consider netscape netting to hold it in place but if that is not in the budget either, just go with straw.
Consider breaking it up into bite size chunks of a couple thousand sq feet each and address them one at a time.
I suggest you think about selecting some chunks near the house that you want to work this year and bite the bullet and seed the rest with rye so that you get some roots in to hold the soil until later. (i.e plot out about 10k sq ft or so close to the house, this spring seed 3k sq ft of that -or whatever you can confortably cover with the sprinklers- with your KBG, use straw and netting for that. Plant the rest of the yard with rye or a contracters mix and cover with straw if you can afford it. End of summer- late August), tackle the other 6k sq ft of the 10k by killing the rye with RoundUp and scalping, cover that with straw and reuse the netting.), Once that comes in, and as time and budget allows, you can kill off another workable chunk of the rye lawn and reseed with your prefered seed to match what you tackled this year.
Other than that, I got nothin. Good luck.

Forgot to address watering. As you said, new seed you want to keep just moist constantly ussually three waterings 4 hours apart will do. Once it sprouts you'll water twice a day for a week, then ever other day for longer periods for the next two weeks. For the spring planting, you'll need to water regularly (3x a week?) through the summer.
BTW, I had problems with slopes in my back yard and seeded with a 50% rye, 50% fescue and added some of my preferred KBG mix 4 years ago. Rather than kill it off and kill the KBG that did take, I scalped it every fall and overseeded with my prefered KBG. The KBG has done quite well in becoming predominant. (Just in case you hate to kill off any rye areas where your kbg did kinda come in.)

After you make it through the summer heat, you can start to back off on watering frequency and go up on watering depth. Generally you should be able to go to once a month watering in the cool months and gradually move back to once a week watering in the summer heat. This schedule is for established lawns. You should get come cat food or tuna cans and test your sprinkler system. Put the cans around the yard and turn on the sprinklers. Time how long it takes to fill the cans. Every sprinkler system is different. Applying one full inch (one can) per month/week is the starting place. Then adjust based on how the grass looks, not how the soil looks or feels. The soil surface should dry completely before the grass starts to wilt.

Thanks for all the advice!

I have a question about incorporating some annual rye in with the KBG seed. If I were to go to a 25%ish percent (by seed count) of annual rye, and the rest the KBG blend I want, would that work? The thought being that the little bit of rye would spring up and help hold onto the soil until the KBG germinates.... Since it is still 75% KBG, I should see a decent population of KBG this year, no? Then next year the rye does not come back, and the KBG spreads to fill in where the rye was... I realize that best case, the KBG lawn would be thin for year two, with the rye gone, and the KBG still trying to establish itself and spread into the vacant space...
With a little patience and weed killer for a couple of years, would the result eventually be a really nice KBG lawn??

Along with the rye, I would also use straw to help with the erosion problems....

What is people's thoughts on this?

Thanks again, I really appreciate it!

No matter what you do, the KBG will be thin for the first few years. The first year it sleeps, the second year it creeps, the third year it leaps. So you seem to have a good understanding of what you're getting into. The only issue might be with shade. KBG will not do well with shade.