That is the essence of Toby's newbie advice first stated almost 2 years ago and it still holds true today. The only difference is that he recommended 30% taxes, but 42% is the highest tax possible which will allow you to immediately get back the peasants you hired as researchers in one turn with 100% morale.

To maximize your gains, hire researchers after each turn of study. If this gets too tedious, you can study as many turns as you like before hiring, but the longer you wait the more potential econ you lose.

Be sure to watch your food too. You will have to build a few farm parts or search for food occasionally during this period. In fact, always watch your food. If you're producing a huge surplus you can just to glance at it occasionally, but starvation will cost you much more than not being able to afford to pay your troops.

for a while. I can't say exactly how long, because once I postpone further study of econ, I'm playing more instinctively. I'll spend most of a day's worth of turns searching for land, study 50 or 100% econ...search some more...study 50 or 100% ent.

You'll also need to worry about building. Toby's original advice was to study construction after econ and ent. I prefer just to hire engineers occasionally and save my turns for studying more important things. Economy will always give you ten times your income, entertainment will be essential for getting your pop lost from random and non-random spells later in the game, but const will be useless when you attain a respectable size due to the 50 million gold cap.

Instead of using const to augment my max build per turn, I instead use smithies. When you can build 2 full smithies per turn (30 parts), smithies become more efficient than const turn-wise. Smithies remain more efficient, as every 10 smithies allow you to build another full smithy per turn. I always build smithies in multiples of 15, as there's a bug that causes an incorrect max to be shown on the Build screen if you have partial smithies. With the four newest races - dire wolves, quicklings, vampires, werewolves - you don't need to worry about building full smithies, as the numbers shown in Build don't take their racial modifiers into account and you'll get a pop-up saying you can only build x number of the building anyway.

What I do is watch my food. When it starts dropping I spend a few turns searching or studying...hiring engineers...repeating and then building farms for 1 or 2 turns until it's positive again.

When I have sufficient engineers to build approximately a full market per turn, I start building them. I switch from hire rangers...search for land...repeat to search for land...repeat until I have sufficient gold...build max markets. Markets should be your primary buildings until you can build at least around a full castle per turn. Definitely refrain from building castles until you can build at least 100 or 200 parts per turn. They're just too slow to build. At 30% taxes, only 741 econ is required for the 15 pop one castle part brings in to equal the income of one market part, but you can build 3.33 more markets per turn than castles at 25% of the cost.

A few colloseums are also a good idea, but I've never really decided how many is ideal. Outposts and guardtowers might be a good idea if you're getting attacked or thieved a lot. I don't bother with schools until I begin heavy studying spellbook or military tactics heavily. Training fields will only be useful early in the game when you have a relatively small amount of military. They're suited mainly for players who will be attacking early, which I don't recommend for anyone but the best players.