Most of you won't read everything, so I'll summarize here:
Always do Quests 1-13. No matter what.
After 13 adventures you've built a rally point, 2 of each field, and only spent a net of 80 resources (less than a rally point costs).
If you get a load of resources from your first adventure, you should finish all of the sequential quests (1-24). A load of at least 175 resources each eliminates all waiting for resources, and your only limit is build time (or starting your second adventure if you spam gold), you can get to the market, NPC, and be immensely better off(on .de I got 346 of each resource on my first adventure; using just the intro gold I had a market and a barracks in under an hour with 2675 resources to spare -> 10 mace, 8 phalanx, or 6 legos).
If not, play to your preference, but here's my suggestion: if your first adventure is cages then you should be able to clear a nearby oasis and raid it for nearly constant income until someone else notices (they have at least 4k resources and decent regen). If not, check your map, if you see a cleared oasis, go for the raiding. If you get a book on your first adventure you can put all your points in strength and again you can probably clear an oasis. If your first adventure is something else, I suggest first option for Teuts, second for Gauls, and third for Romans.
(with no golding takes under an hour, rally point is instant finished):
Finish quest 10, queue MB 2 and 3, THEN finish quest (11) so you don't overflow.
Teuts/Gauls: for quest 11 switch production to wood.
Romans: Switch Production to Iron.
After quest 12:
Teuts can build 4 maces, and another in under an hour with resource bonus on wood.
Gauls can build 3 phalanx, and another in 1.5 hours with resource bonus switched to clay.
Romans can build 2 legos, takes about 3 hours with resource bonus switched to wood.
ALL of these are better than stopping after any earlier quest, and better than rushing barracks immediately (although only slightly for Romans, sorry Romans).
Somewhat Early Raider
Quests 1-16 in under 2 hours
If you start right away and don't see any oases nearby that are already clear, you might want to wait a bit so there's actually something for you to raid - personal preference I guess.
Finish quests 1-10, queue two more fields, THEN switch resource bonus to clay for quest 11. Immediately switch resource bonus to wood (you will lose out on 8 resources, but finishing the fields faster is worth it). You might get stuck on 13 depending on the length of your first adventure - just start building the fields to 1 for 14.
Quest 14 will take a while to complete, and if you gold everything and pick clay you'll be 65 wood short, thus your limit on completeing 14 is the 1ish hour it will take to generate 65 wood.
After quests 15 and 16:
Teuts can build 3 mace
Gauls can build 3 phalanx
Romans can build 1.5 legos... sorry Romans not so good for you
Finishing the Sequential Quests
(Under 12 hours, depends on adventures)
Follow the previous bullet up to Quest 14. Keep the production on wood for now, you'll need to split your time evenly between wood and clay to finish 17 in the optimal time. This can be a bit of a wait; you'll be short 175 wood, 65 clay, and 175 iron if you did everything as I said. If you leave resource generation at even, you will get 8 more resources per hour, BUT, if you split time evenly between Wood & Clay, you'll get 2.5 times as much wood and clay and you can finish the quest faster.
Once you're done with quest 17, you'll have a slightly shorter wait for quest 19, but after that's done your rewards pay for everything along the Economic path, and the market reward is 2k resources which you can then NPC into a bunch of troops. Alternatively, some of the second tier quests give you more resources than they cost, so consider Embassy, MB to 5, and granary to 3.