I am about to start a new lawn and wanted to get some recommendations
on seed. I have read several places that you should buy the best you
can - trying to save money on the seed isn't worth it in the long run.
So, what brand/type is the best? Is there anything I should look for
besides the lowest percentage of weeds? I think that is listed on
every package, correct? I am probably looking to get a fescue or
fescue/bluegrass mix.
I have also read that seed can degrade in the heat and over time.
Where is the best place to get fresh/well kept seed? Would Lowe's or
Walmart be good enough? Are there good internet dealers?

Also, I am tilling up what grass and weeds I currently have on the site
and fertilizing before planting. I have already killed it all with
roundup. Do I need to remove all the dead grass and weeds, or can I
leave them in the soil after tilling? Seems to me they would just add
some organic material (which the soil could use).