Here's a quick guide as well as a couple recommendations:
You play as the 'owner' of a plot of land in the city-state of Plantera. Your plot is unique because it is is located above a collapsed gold mine. The innumerable corpses of dead miners have made the land extremely fertile. You are technically still on the king's land and he has not given you permission to hunt here. This will be important later.
Now, you start out with an empty plot and a single serf. Luckily for you, the peasantry of Plantera are starving and will pay through the nose for anything edible (note that their diet consists of fruits, vegetables, insects, milk, eggs, and the occasional boot). You should begin by harvesting a few butterflies. Do not touch the ladybugs, I'll get to them later.
Until you've established yourself as a reputable land owner, nobody will sell you more advanced plants. You'll have to start with carrots. I recommend planting a few carrots, but only until you can afford some larger plants and trees. The local wildlife has been starving for some time and the rabbits will not hesitate to raid your carrots. You can scare them away but this gets annoying real quick as there is a veritable army of them and they've already cleared out all of the peasant farms.
You'll want to make sure that all available bush/vine and tree spaces are full at all times. Always buy the best plant possible. Your goal here is to grow enough fruit that the birds, who want your fruit to feed their famished young, will be able to pinch a few apples here and there without cutting into your bottom line. You can try scaring them off but they will always come back and, being avian, are slightly harder to swat then the rabbits, i.e. not worth the effort. Don't bother replacing old plants until you've unlocked the top tier ones. Prioritize trees over bushes/vines when applicable. They produce 5 fruit at a time as opposed to a bush's 4.
Ground plants: pumpkins are too heavy for the malnourished hares to abscond with. Plant these as soon as they are unlocked. Skip the radishes and turnips. Eventually, you can upgrade to cabbage. Cabbages in Plantera are oddly dense. Small mammals cannot unearth them and they seem to take your serfs considerable effort to harvest.
Animals: Chickens and sheep are not a good investment as they will be relentlessly pursued by predators. Remember, only the king and his retenue may hunt in Plantera. Wait until you've unlocked the pigs. The pigs will dig up fertile soil, boots from the dead miners, coal, and occasionally gold nuggets. Unlike with plants, you shouldn't blow all of your money on pigs. Just purchase a few (up to 5) to get started.
Land expansion: expand whenever you can. Each extra acre of land will displace another villager who will have no choice but to work for you. Early on, you may feel compelled to contribute to the harvest. Once you hit around level 10 let your growing army of serfs handle to grunt-work. The sun never sets on Plantera and you are too important to be laboring out in the heat.
As you begin selling more and more expensive produce you will begin to gouge the surrounding villages. In response, villagers who are unable to feed themselves will pledge themselves to your service. You should get another one every couple levels (seems to be every 3 but I may have miscounted).
Speaking of gouging, whoever is selling you your plants and livestock will jack up their prices based on how many of each item you have. The best way to deal with this is to never spend more than 2,000 - 3,000 gold on any one item until you reach the top tier. You'll probably end up throwing it out (no refunds) and you don't want to waste the cash.
Ladybugs: Your farm will attract a new ladybug with every level (they may appear randomly as well but I can't confirm that). Ladybugs, a delicacy in Plantera, are worth your level * 10 gold and should be saved up as they greatly increase in value over time. Ideally, you should wait until after level 20 to harvest them. Wait too long and the rising cost of new plants will outweigh the benefit of your investment. I recommend waiting until level 30 at the absolute latest.
Once you have unlocked the top tier plant for each space, begin the process of replacing your old plants with the new and improved ones. Never leave an space empty and, always remove your least profitable plants first.
The cows, though prohibitively expensive, produce both milk and fully formed glass bottles which you can sell as a pair for 15 gold a pop. You want to max out your animal capacity (11 total) with cows before you begin to discard your pigs. Remember, don't throw out a pig unless you are at capacity and can replace it with a cow.
Other characters to watch out for: There is a lonely mole who will occasionally pop up out of the ground. He is shy and will only hang around for a moment. The mole desperately wants physical contact. If you grace him with your touch, he will raise his arms in ecstasy and pay you for your time. The mole pays 1 gold per your farm's level.
There is also an errant knight who has to pass through your land on his way back from pillaging. He will always come from the West/left and exit through the East/right. Out of respect/fear, he will not harm your serfs or animals, nor will he take anything from you. It is worth noting however, that he is loaded with ill gotten spoils and is trespassing. Smack him around and he drops gold. He will drop 1 gold per your level each time you click him. Be careful not to crush any of your ladybugs as you rough up the knight. I suggest aiming for his head/upper body.
Late game: After level 20 or 21 you will start to gain some prestige. In the order that you unlock things, you will gain a gold star next to each item with each level. First your carrots, then your blueberry bushes, etc. These stars mean that you will now be able to sell whatever that item produces for one additional gold. You may be tempted to remove your better plants in favor of the cheaper, suddenly more lucrative ones, but don't do this. Eventually, these prestige upgrades will reach your top tier items and buff them. I'm not sure at what level these prestige bonuses stop. I'm at 41 and it looks like they stack up to at least 2 or 3 but I cannot confirm this.
One last thing: You cannot expand your land more than 3 acres or hire the guard dog in this version of the game. I found this disappointing. The dog wouldn't be much use, seeing as the cows don't require protection but the additional land could drastically increase your earnings.
Good luck.