Holy crap. Well, here's the real short version of how to get a perfect lawn in a few easy steps. It basically comes down to four rounds of fertilizer, two weed sprays, one round of overseeding, and possibly one soil ammendment per year.
1. Find a local turf company. Best way is call the groundskeepers house at your local golf course, and ask where they buy their seed and fertilizer. They work early hours this time of year, so catch them early in the AM.
2. Get a soil sample. At a minimum, you need to get your pH in a good range before spending any $$ on fertilizer and seed.
3. Get your grub and insect control down in the next two weeks. Around here we use Allectus in a 16-0-0 fertilizer mix.
4. Might as well do the soil amendment (pH adjust, eg. Physiocal) now, as well, as any money spent on fertilizer and seed will be wasted if pH isn't right. Warning, this can be a LOT of material, to the tune of 1000 lb./acre, if your pH is off more than a few tenths. Good thing is, it's very cheap.
5. Come mid-August, or whenever your grass is past the summer stress, spray lawn weed killer. We usually use Surge.
6. Four weeks after lawn weed killer, run the plug aerator, then overseed and starter fertilizer the entire property. This is the one real big $$ expense of the year, as good seed ain't cheap. Make sure you choose a seed that will weather your local conditions well, since again... it's not cheap.
7. November, put down your winterizer fertilizer.
8. As soon as the snow melts (March, around here), collect your annual soil sample, and get your pre-emergent weed and feed (eg. Prodiamine) down. Adjust your application rate to have it fully played-out before September's over-seeding. Take soil sample to turf company for analysis.
9. Put down whatever soil amendment (pH adjust) the soil analysis recommends. This will be less than the prior year.
10. Late April, second round of fertilizer. This can be combined with weed killer, to get the weeds that do come up, or you can spray separately (eg. Escalade2).
11. Hey... we're back to June, see Grub control with fertilizer.
Time invested = 4 hours per acre per year
Money invested = $400 per acre per year without seeding ($1000 per year with seeding)