I recently planted a new lawn. Today I am exactly 4 weeks into the lawn and mowed it for the first time. It is coming in great. I have good black dirt, I put straw down, and got water on it every other day. My question is what do I do next? When do I put fertilizer down and what kind? When can I put a weed killer down? The lawn is coming in great but like every new lawn there are some weeds.

Basically when should I fertilize and what should I put down?