Bad Moon is a moon sign that = teh win, if you're willing to make sacrifices. To unlock it, complete a hardcore ascension* without using a ten-leaf clover.
One of the main ideas behind Bad Moon was that it will give you something, but at the same time take something away from you. This can be demonstrated even in the rewards, because they give you +50% to one stat while giving you -20% to another stat. However, if you have all of the rewards (or other "give and take" items/skills), they will help you.
Welcome back to the Kingdom of Loathing. Noob.
So, you just ascended. What do you do? Start out with stuff you normally do, and unlocking stuff that will help later, such as Spookyraven Manor. Also look for the +20 mainstat adventures that can be found in Cobb's Knob (muscle), the Sleazy Back Alley (moxie), and the Haunted Pantry (mysticality). Those will help you gain immediate access to your guild.
Meat is pretty important. There are 7 new skills to buy (get all 7 and they help you, but without all 7 they help you but at the same time slow you down) as well as the skills you can purchase at your guild. Well how do you get the meat to buy all these skills?
Gain Loss Area, Pre-Condition
* Onna Stick - 3000 Meat -20 Moxie, 10 turns Bat Hole Entryway, beat Boss Bat
* Flowers for (familiar) - 2000 Meat -20 Mysticality, 10 turns Degrassi Knoll, build your meatcar
* This Doesn't Look Like Candy Mountain - 1000 Meat Missing Kidney (no effect known) Spooky Forest, none
* A White Lie - 5000 Meat All Attributes -20% Whitey's Grove, opened the Road
* The Beaten-Senseless Man's Hand - 4000 Meat Beaten Up, 10 turns South of the Border, none
Once you've gotten some meat and a few skills (Meansucker's Skills that you may want to get right away are pride and envy), time to start doing stuff. As in, get some familiars. Get the familiars you will need for the tower (get the potato from the Bad Moon adventure The Placebo Defect in the Conservatory), get a fairy and volleyball (not necessary, but nice to have), start doing the Daily Dungeon, etc. Leprechauns are not worth it unless you get lucky and pick one up right before the level 12 quest, but even then they aren't worth the adventures to train them.
As for low level equipment, try to get the Knob Goblin Elite Guard uniform. And the Lab key. The Lab has a few nice items (including the knob pet-buffing spray, excellent for the tower) and you can pick up the irradiated pet snacks while you're there.
Killing ratsworth may or may not be worth it depending on the class you pick. This run I did not fight him, but last run I did. If you are in Bad Moon you probably have some experience with when to fight him and when not to, and it's entirely up to you. If you're a pastamancer, entangle your noodles upon him and watch him die as your teh awesome spells kill him. also, i heard from somebody in /hardcore that a Poltergeist-in-the-jar-o is a really cheap and effective way to kill him. I think they drop in the Cemetary.
Go get daily buffs from the Styx Pixie! He is awesome!
I really like the LEWs because they really help you out until you can pick up some better gear at about level 8 or 9. Again, it depends on your preference.
As for food, a chef-in-the-box = teh win (don't kill me for not picking one up yet snooty i'm sorry!!). cooked foods rock, and i think you can make potions with it as a sauceror (somebody look it up, i'm not a citb expert).
Snooty also picked up the Spookyraven skill for me this run, so I am assuming that it is good (i am a pasta). The TT skill is generally the awesomeness so you may also want to check that out. I don't know about any of the other ones though, as I have not ever used them. Unlocking the ballroom early also helps with the level 11 quest.
Some skills I like...
-All the Meansucker skills. Combine them, and you will win. Lust for pastamancers is especially helpful, even though you get the -5 spell damage.
-Spectral Snapper and Fearful Fettucini
-Torso Awaregness. Yes, you can get the torso. Unlock the Hidden Temple early and go back to the Forest to snag it. It gives you -50% Muscle for 5 turns but I think it is worth it.
* You may use clovers after freeing the King.