So you're probably here if you're new to Attack of the B-Team. In this wonderful modpack there are many branches to delve into. I suggest starting with normal Minecraft objects. Here is a list of instructions to get started.
1. Gather wood
2. Skip this step if you have starter gear from a multiplayer server. Make basic tools (e.g. stone pickaxe, sword, shovel and axe)
3. Make a base (preferably underground) If you are on multiplayer use a golden shovel to claim your base. The tutorial is here http://tinyurl.com/layw6oc
4. Place some chests and a crafting station in your base.
5. Go on an epic mining spree! You should have at least 15 iron ore collected before you stop.
6. Craft some furnaces and maybe make some home improvements such as installing cobblestone floors.
7. Make babies with hot chicks