From the original post "Obviously there is a dead tree that needs to be removed as well." The jason777 said the tree is dead is there a reson to keep it? Maybe I was't clear on why jason777 should use Tenacity, maybe gsweater didn't read the original post, or maybe he/she doesn't understand Tencity's use as a preemergent herbicide that you can seed cool season grass into. I didn't even address the OP's question about dandelions, you can use 2,4D. By the way gsweater what is it that you recommend jason777 should do? So gsweater I'll lay it out for you in simple chapter and verse since you clearly don't understand the issues with seeding in the what would now be considered late spring,and I'll try to keep it short and use small words so you can keep up. To seed you need to have good seed to soil contact,so you will need to aerify and/or rake up all the dead stuff. Once you've disturbed the soil, seed and then roll. Use Tenacity right after you seed and then again 3 weeks later, watered in with .15 inches of water. Three weeks after the last application of Tenacity apply the low rate of prodiamine or pendamethlin, be careful not to apply to much because your probably going to need to reseed a few spots in the fall. Now after you seed you have to keep the seed wet for around 10 days if your using tall fescue if your using kentucky bluegrass it's more like 21 days, this means watering for a couple minutes every hour or two between the hours of 8 a.m. And 5 p.m. Once the seed has germinated you can back off the water to twice or three times a day until the tall fescue has tillered out a couple of times, or the kentucky bluegrass is starting to put out rhizomes. Also, as soon as the seed germinates you need to feed it some nitrogen something quick release, like ammonium sulfate or urea, so you can get it moving to out compete any weeds. A .5 of a pound of nitrogen per thousand square feet every couple of weeks until the area is filled in. Okay now the area is mostly covered and it's now the end of May or the beginning of June just in time for summer heat and disease pressure. Also, now that the plants are hopefully mature enough you can start spraying any weeds that the Tenacity missed.Take a picture now because by the end of August that area is not going to look like it did in May. The plants that you seeded back in the end of April beginning of May did not have enough time to develop a deep root system and store enough carbohydrates to fight off the heat, drought, and disease pressure that is coming. Now,if you sod you cut out the area,rake, lay the sod,roll if you need to. Give the sod a good soaking once in the early morn. with a hose. The sod should be rooted down in about a week. Once the sod has rooted down apply pendamethlin or prodiamine and water in with .5 inch of rainfall or irrigation. Then one shot of fert at .5 to a 1 pound of nitrogen per thousand square feet. Or the best option wait until early fall and resod then and you don't have to worry about preemergent herbicides and the sod has all fall,winter,and spring to develop a strong healthy root system.

Looks like crabgrass.

Update #1 I know I haven't technically gotten into the "lawn care" part of my backyard makeover, but I figured I'd give y'all an update anyway. My attack plan is to build our paver patio first, then work on reseeding the lawn when it gets cooler in a month or so. Here's where things stand after my first weekend working on the yard. See my original post for a 'before' pic of the yard. My goal for the weekend was a little too ambitious (especially considering it was 100 degrees here in Richmond this weekend): Take out the garden fence; cut down the garden plants; move the wood pile; remove the deck. The garden fence was waaaaay overbuilt with each post buried 3-4 feet down with two feet of concrete at the bottom. I had planned on pulling them out but I ended up just cutting the posts off about 8 inches below grade. The deck was similarly over built, with joists about every 10 inches. The guy used nails to build it instead of screws, which meant I have to cut on either side of each joist with a circular saw or else pry each board up. I'm about 2/3 done with the deck. The wood pile was a beast. About 200 cu ft of wood. I built a new rack for it and stored it against the back fence. This was the most time consuming job of the weekend and the hottest. That stretch between the old location of the wood pile and the new is only in the shade at dawn and after 6pm. We also got the two stumps ground on either side of the yard. They were ground to 8 inches below grade. This week I'll be spraying RoundUp against the fence on the left for the new raised beds and building those beds. I'll be filling them with the soil I excavate for the patio where the deck used to be. One quick question that didn't get answered above: Would this power rake rental from Home Depot do the trick for getting an inch into my soil to loosen everything up? It looks like the tines are loose and pivot on the central axel. Seems like I might need something with fixed tines. Any advice is appreciated.

Some sort of weedy allium, maybe Allium canadense, wild garlic.