Broken Steel expansion pack adds fourteen new perks to the game. You should also know that these talents are all connected to the increased level cap, so you'll be allowed to choose them whenever you advance to a higher experience level. The first group of perks will become available when you reach level 22 and some of the most powerful talents are reserved for level 30 characters.
I would like to inform you that you won't be able to get to 30th level of experience if you'll only rely on new quests. All six challenges (three main quests and three side missions) won't get you past levels 24-25 so as a result you'll have to look for other opportunities of earning experience points. I would recommend installing other DLC's, as well as fighting supermutants, deathclaws and other powerful creatures. Don't forget that in some areas in Broken Steel you'll be dealing with endless enemy reinforcements until you move on to other section. You'll be allowed to use this to your advantage in order to earn a lot of points easily.
Here's a list of new perks:
Deep Sleep - lvl22; ranks: 1
Effects: Sleeping (even if someone elses bed) results in a 10% experience points increase that lasts eight hours.
Additional info: Interesting perk, but only if you prefer to heal injuries using sleep instead of standard stimpacks and other medical supplies.
Puppies! - lvl22; ranks: 1
Effects: Each time Dogmeat dies you can get a new dog from the entrance to Vault 101.
Additional info: Useless perk. Choose it only if you want the dog at your side badly and if you've already lost Dogmeat once. Otherwise you should choose something more practical.
Quantum Chemist - lvl22; ranks: 1
Effects: You can manufacture Quantum Nuka-Cola using ten bottles of Nuka-Cola.
Additional info: Consider choosing this perk only if you haven't completed Nuka-Cola Challenge subquest and if you're too lazy to look for Quantum bottles on your own. Otherwise ignore this talent.
Devil's Highway - lvl24; ranks: 1
Effects: Your character's allignment is automatically set to very evil.
Additional info: Yet another useless perk. You can lower your karma without its help by attacking helpless wanderers, blowing up Megaton or destroying the Citadel.
Escalator to Heaven - lvl24; ranks: 1
Effects: Your character's allignment is automatically set to very good.
Additional info: Similar situation to the previous perk. It's more difficult to gain positive karma, however I assume that you've made up your mind at the beginning of the game whether you want to play as a good or as a bad character.
Karmic Rebalance - lvl24; ranks: 1
Effects: Your character's allignment is automatically set to neutral.
Additional info: Third karma-based perk. It's slightly more useful, because usually you have to spend more time trying to reach neutral status.
No Weakness - lvl24; ranks: 1
Effects: All main stats are being raised to 5 points.
Additional info: Guess what... another useful perk. You can raise your main stats easily and without having to choose a perk. I recommend taking part in some of the subquests and collecting Vault-Tec figurines. Spend your point on something useful.
Nerves of Steel - lvl26; req: Agility 7; ranks: 1
Effects: Faster regeneration of action points.
Additional info: Finally something that's interesting. Using this perk can make some of the toughest parts of the game easier, because you won't have to wait too long before you're allowed to use V.A.T.S. system again.
Rad Tolerance - lvl26; req: Endurance 7; ranks: 1
Effects: You won't receive penalties from minor radiation.
Additional info: Worthless perk, mostly because minor radiation won't result in any large penalties. Besides you can heal yourself easily and you should have armors that offer good protection against radiation.
Warmonger - lvl26; req: Intelligence 7; ranks: 1
Effects: You don't need the schematics anymore to construct unique weapons.
Additional info: This is an ideal perk for a lazy player. :-) You won't have to spend additional time anymore trying to get to the schematics. I wouldn't recommend taking this perk, especially since custom-made weapons aren't that good and it's not that difficult to manufacture them on your own.
Party Boy/Girl - lvl28; ranks: 1
Effects: Your character won't receive any penalties from drinking a lot of alcohol and being addicted to beverages.
Additional info: Wanna guess? Yes - it's a useless perk! Choose something that you can actually profit from.
Rad Absorption - lvl28; req: Endurance 7; ranks: 1
Effects: You begin losing radiation points over time.
Additional info: I would only recommend choosing this perk if other useful talents are already on your list. Still - you can achieve the exact same effect thanks to medical supplies (Med-X and RadAway).
Almost Perfect - lvl30; ranks: 1
Effects: Your main stats are all raised to 9 points.
Additional info: A very useful perk which will allow you to achieve total dominance while exploring the Capitol Wasteland. Nevertheless, you can achieve similar results if you've already collected all the figurines and completed all subquests with stat increases as rewards.
Nuclear Anomaly - lvl30; ranks: 1
Effects: The main character explodes each time he has less than 20 health points.
Additional info: This is by far the strangest perk you can get in the game and I would recommend choosing it for fun. Remember that the explosion will hurt everybody, including your allies, followers and innocent civilians.