I think you have quite a bit of broad leaf plants, spray it with 2,4-d, knock out every thing except for grass and sedges. Once you get that far, a month from now, prepare for the winter. You may then consider seeding in the late fall.
In the spring, you might want to put down a pre emergent down and/or then focus on specific weeds. Dont do the pre emergent if you planted seed in the fall.
At any time you can spot treat with glyphosate (round up).

I agree with you assessment. Front is salvageable, back needs the work.

I disgaree with the FLA 2,4D recommendation though. 2,4D is great for those salad greens but you need stronger for the barnyard grass/crabgrass (can't tell from far away pictures)

Spraying herbicides in high heat like we have is detrimental to the existing grass. Thing is, I don't see much grass in the back yard to worry about. So here's what *I* would do for now.

Buy Weed B Gone w/Crabgrass Killer concentrate or the Spectricide equivalent, the key ingredient is Quinclorac. Apply a blanket application on the back using an Ortho 'Dial A Sprayer'.

Few days later, start irrigating the whole lawn, watering well. Front and back. This wakes those weeds up.

2 weeks later, spot spray any weeds that spring up or were missed the first app. in the back.

Labor Day, seed the back yard.

Labor Day, fertilize both the front and back yard.

The fertilizer will get any weeds growing in the front, spot spray as needed.

October, repeat fertilizing on both lawns and weed control on the front only. (if you have mowed the new grass 3 times by now, you can gently spritz the back yard with he weed killer too)

November, repeat above on both areas. Back lawn is now mature enough for weed killer. Fall is the best time to kill weeds since most are winter annuals. Killing them in fall means little to none the next spring.

Then next spring, in the St. Joe, GR, Kazoo SE MI area, late March/April 1st, apply a pre-emergent WITHOUT fertilizer. You can buy Scotts Halts alone, without fertilizer at Ace Hardware.

(there are other vendors that sell better/cheaper products geared for pros, that a private home owner can also buy, but for now, we;ll keep it simple and use Ace)

Then in early May, once you are cutting actual grass regularly and frequently .... you apply your first fertilizer of the year - and repeat the above! Keep up with any weeds, spot spraying as needed and wait until Labor Day to fertilize again.

No need for marketing BS, applying steps 1 through 86. Once in Spring and a couple/few in fall, and you'll be the envy of the block with green grass and all weed free.

Thanks for all the recommendations! :) I greatly appreciate them and will get started on it!

I have a few more questions now if you don't mind.

First off, as far as watering well, should I be watering every ciuple of days or heavy (1") a week?

Also, as far as fertilizing - is there anything inparticular I need to look for? A weed and feed type product or just plain ol' fertilizer?

Thanks again!

Other than when you're getting new seed to germinate and then helping the new grass seedlings to get started, always water deeply and infrequently. It helps the grass develop deeper root systems and makes it less likely that weeds will germinate.

Weed and feed is great from a marketing perspective. It's not so great from a useful perspective. It sounds good, but weeding and feeding are different things and should be done separately. Weed killer will work better if you fertilize first. That will get the grass (and the weeds) growing vigorously. When they're growing vigorously, the weeds will take in more of the weed killer and it'll be more effective. Unless you've got a lawn that is inundated with weeds, you're better off spot spraying--just spray the weeds, not the whole lawn.