Do I really need to chill?
If you can. I made these cookies over the course of a few days. Greg couldn't wait the standard 24 hour chilling period, so my first batch was only chilled for a few hours. They turned out great, yet I noticed the batch that was chilled for 24+ hours was slightly more attractive.
Salted vs Unsalted Butter?
When I see recipes explicitly say "use unsalted butter", I generally roll my eyes. As if the extra tiny bit of salt is going to cause your recipe to completely fall apart. In my opinion, it doesn't matter what kind of butter you use, and if you're worried about your recipe being overly salty (but all you have on hand is salted butter), just don't add quite as much salt as the recipe calls for.
Do I have to sift?
I may roll my eyes at the butter debate, but I am a firm believer in sifting. Just make up your mind that you're going to be a sifter, and it's all down hill from there.
At what point can I add eggs?
Now this is important! Next time you make cookies stand by your mixer and watch the dough during the butter/sugar stage. There will be a point in time (about 2 minutes in) when you see the color and texture change - it will be considerably lighter, and look fluffy. At that time, you can add your eggs (one at a time), then watch again, you will see the color get even lighter, and the texture even fluffier. Once that happens, you'll be ready to add the dry ingredients.
Use parchment paper—it'll be your best friend, plus it'll save you clean up time. Salt the top — I'm telling you: YUM! I like to use a giant ice cream scoop to get the perfect size (think the size of an apricot). Pull them out JUST when the edges start to look golden.