Game Phases (Guide)

Guide in progress. Feel free to edit or improve it. I'd like to have some list of quests that can be completed when you're in that phase, if anyone wants to help add that. This list is based on the resources that unlock more things you can make or quests to complete.

Flint
When you first start, you have access to flint and dead wood, not much else. You'll want to quickly make a set of tinker tools, following the quest Such a Tool. You'll also want to start breaking the meager dead grass you find to start getting seeds. You should also go underground to get some cobblestone and dirt, probably in the first few nights.

Seeds
Lots of Agricraft crossbreeding here, trying to get different types of seeds. You'll need a lot of sticks to make crops, and liberal use of NEI to see what will breed into which seeds on what types of soil. Once you have two mandrake root, you'll be able you make mutandis, which will get you saplings. You'll still be crossbreeding crops for quite a while, so setting up a strong farm is a good idea.

Trees
You now have access to a renewable source of wood. Now's a good time to start working with Botania, if you haven't already. The floral fertilizer used on grass will get you magical flowers, which you can craft with a book to get you the Lexica Botanica. That will explain how to use Botania. Once you've created a runic altar, you can use it to make magical crop seeds. To get the essences you'll need for the first few, you can complete quests in What the World is Built From. When you have the choice to get skeleton seeds in (in)Fusion-HA!, take them. The bonemeal will be quite useful, and you won't have to summon them later.

Metals
Now that you've gotten some magical crops seeds growing, you'll start having metals. At this point, there are so many things you can now make. Continue crossbreeding and improving your magical crops and check out the countless new quests that unlocked.

Nether
You'll need to go to the nether to get your first nether essence which will unlock several more types of seeds. You don't need to actually do anything in the nether for a little while- but be warned, the zombie pigman will attack if they see you harvesting ore.