Is your soil clay? I wouldn't recommend a rototiller if so!! You'll end up making concrete. If your soil is very, very dry you can use the tiller to break up the surface by quickley walking it over the top just to break up the top of the soil. Now you should be able to hand pull/gather the majority of weeds.
Of great importance will be filling your pool area (you did remove the pool itself, yes?) and systematically compacting the soil in layers as you fill. Rent a compactor for this job. If you don't you'll be seeing a huge hole in your lawn as the soil settles and compacts on its own!! Bring in a load of topsoil (figure sq. ft. divided by 81 to give you cubic yards to purchase for 4" depth of topsoil over lawn area...if that is too much divide by 2 to get 2" which will ensure no perennial weeds will thrive) spread over area and use your tiller again to slightly breakup and mix this new soil with your existing soil. Slightly. If you've got clay do not try to fluff and rototill too much if at all when even a little moist! Do not use peat moss! Too acidic for a lawn.
Using a large grading rake grade and grade and grade. Allow a slight slope to allow water to drain...somewhere. At least 2% slope (rise/run = slope). If that pool is still there you are going to end up with a bog of mud! Use the concrete of the pool to make low garden walls somewhere!!
Before laying sod, rent a roller. This you fill with water and compact the soil on top. Use your grading rake to fill any holes that show up and reroll. Now you could also spread fertilizer for your lawn. I'd go and spend a bit more to get an organic lawn fertilizer instead of the synthetic stuff. Dr. Earth makes one that blew me away!! Worth the cost and you don't have to fertilize as much (2X/year versus 4X/year), it also comes with mychorrhizae and bacteria. Use a mechanical hand spreader DO NOT THROW BY HAND!!
Time to lay sod. Make sure the sides of the sod touch and that no grass gets caught in the seams. Do an offset pattern and preferrably perpendicular to the main line of sight. Again, use the roller on top of the newly laid sod to ensure good contact with the soil. If you see holes, simply grab the grass like hair, pull up put soil in the hole and replace the sod. Roll again. Water well. Not by hand. Get yourself, if you don't have automatic irrigation, a cheapo oscillating sprinkler. These are my preferred watering tools!! Soak until the soil is wet at least 2 inches deep. Allow to dry before soaking again. Once your grass is rooted (week or two) start training your grass to develop deep roots by watering deeply (work up to 6" deep) and do not water again until your footprints on the grass stay down. This is forcing the roots to grow deep to reach moisture and takes a few months.
Never, never mow shorter than 3". If your mower can't be raised high enough then I would go get another one!! Keeping your grass at this length helps make a very healthy root system, shades the soil so no weed seeds can germinate and also slows water loss. Always have a set of sharpened mower blades to change out dull blades that rip and tear instead of cutting.
You'll have the darkest green, soft and cool, weed freest lawn EVER...I guarantee it! Oh, once per year, aerate with an aerator that PULLS PLUGS once per year. Leave plugs on top of lawn to disintegrate. Fertilize with an organic slow release LAWN fertilizer spread with your mechanical spreader twice per year (read and follow direction for amount to put on lawn) and make sure you blow off all fertilizer from concrete. Get yourself, if you don't already have one, a line trimmer to vertically trim edges between plant beds, concrete. Careful not to 'scalp' edges when horizontally trimming. Keep at 3" high!
Shoot, and it would be a great idea to test your soil. Free or cheap soil tests are done by your closest Extention Service put on by a main university. Lawns need a more alkaline soil than do most of your plants. Do not add lime unless you KNOW what the pH of your soil is and how much to change your pH.
Not easy but worth it if you want great grass. If people really knew what it took to raise these monsters, a lot more people would chose a gravel understory...grin!!