Educate yourself about lawn care, then you can make an informed decision about what practices you wish to follow. In New Jersey, Rutgers has an excellent turfgrass program and you can learn information geared to your location:
http://njaes.rutgers.edu/garden/
Their site takes a bit of digging to get to the good instructions. Here's their page linking to their fertilizer PDF:
http://njaes.rutgers.edu/garden/faq.asp?c=6&s=31
Fertilizing your lawn without a soil test is like taking cholesterol medicine without a blood test.
Regarding Scots, it is an excellent product, but you are paying for consumer marketing and brand recognition, like the difference between Bayer aspirin and Rite-Aid aspirin. They contain the same ingredients.
Check out your local John Deere Landscapes dealer for high quality Lesco lawn fertilizer. I get a 50 lb bag of slow release 24-0-11 for $20 vs. Home Depots Scotts Turf Builder 32-0-4 at $39 for a 37 lb. bag. They cover the exact same area, with the Lesco having iron and more potassium (if needed). Also check out your farm town grain elevators for their dedicated no-name lawn fertilizer. But, you need to know how to read labels in order to compare products.
A separate broadleaf weed killer will work better than weed n feed, IMO. Once you get your weeds knocked back, you can get your lawn healthy and reduce or eliminate chemicals from your regime, if that is your goal.
Good luck.