So much too say...
If you haven't put down a pre-emergent herbicide yet, do so now. The two most common active chemicals to control crabgrass before it germinates are Dimension (dithiopyr) and Barricade (prodiamine). Look at the label of your bag while at the store. Cheap brands are fine.
At this point I would use something with Dimension as soil temps have warmed above 55 degrees which corresponds to the temp that crabgrass is able to germinate. Dimension (dithiopyr) works a little bit even after germination so I'd use that. Follow up with another application of Dimension around June 1st for added protection as these chemicals eventually break down in the soil. A few people choose to apply a pre-emergent in the Fall too to prevent some of the Spring weeds like Henbit, but you need to be aware of max yearly rates on chemicals before adding a 3rd application. Read your application labels and stick to the lbs of product per 1,000 sq. feet. If you graduate to this level, you'll eventually be putting down these weed control chemicals without the fertilizer added. You're main big box stores pretty much always have Nitrogen included with fertilizer though. Sometimes you don't need the fertilizer.
I generally apply a grub control product sometime in later June or sometimes July. There are essentially two kinds of grub control; the kill now type, and the preventative type. Most people don't ever need the "kill now" type unless they didn't put down preventative grub control.
People work so hard in the Spring when they should really do the work in the Fall. If you fertilized correctly in the Fall, you shouldn't need Spring Fertilizer until sometime in May. Regardless, it's best not to fertilize until the grass wakes up and is growing actively.
On weed control, I'd recommend going to your local Ace Hardware and pick up something called Gordon's Speedzone. It will work better on your Spring weeds than standard 3-way weed control (Weed-B-Gone). Add a could of drops of dish soap to the sprayer and either spot spray weeds, or if you have a lot of weeds walk the whole yard and spray. You can buy a marking dye also at Ace that will show you where you have already sprayed and the bonus is your yard is blue until the dye washes away!
I don't recommend weed-n-feed granular products. If applied on slightly wet grass they work ok for very weedy yards, but most homeowners probably don't apply it correctly for maximum efficacy. If your have a lot of weeds, you're probably better off using one of those hose end sprayer weeding products.
I like to use Miloganite as my fertilizer of choice. It's actually re-purposed sewage from Milwaukee but you basically can't burn your yard and adds biology and carbon to your soil. It's much slower acting then chemical fertilizers, but the addition of iron in the Miloganite gives the grass a nice dark green color. Miloganite is sold at many of the big box stores but not all of them carry it. Regular fertilizer is fine too and it has its place in my arsenal.
You don't need to fertilize in the heat of the summer and I wouldn't put anything down in the hot months unless you have a sprinkler system. Even then, fertilize at half the standard rate.
Spring is not the time to seed beyond spot seeding areas destroyed by the dog. If you have already put down pre-emergent for crabgrass than don't seed. It won't work unless you take some very specific steps. If you need to seed some spots after putting down the crabgrass control PM me and I'll let you know how to get that accomplished.
Properly maintained turf type tall fescue lawns rarely need de-thatching. You'll get differing opinions, but core aeration isn't generally worth it unless you are fighting specific soil problems.