SCOUNDREL - lvl4; req: Charisma 4; ranks: 3
Effects: Each level raises your Barter and Speech skills by 5 points
Additional info: This is one of the better skill-related perks. You'll be able to accomplish a lot with high speech skills, especially if you're playing as an intelligent person. As for barter, you can get better prices from merchants. Consider spending at least one point on this perk, unless you're absolutely not interested in any forms of interactions with NPC's.
IRON FIST - lvl4; req: Strength 4; ranks: 3
Effects: Each level raises your Unarmed skill by 5 points
Additional info: Pathetic perk and something you should NOT be interested in. Not only you'll receive a bonus to only one skill, but it's also a useless one, because instead of raising it you should be more interested in Small guns or even Melee weapons.
DEMOLITION EXPERT - lvl6; req: Explosives 50; ranks: 3
Effects: 20% extra damage dealt using explosives (grenades, mines and rockets)
Additional info: You should consider choosing this perk if you plan on raising Explosives (mines, grenades) or Big guns (rocket launcher) to the maximum. The difference is a significant one, especially when you achieve the final third rank (60%!).
LEAD BELLY - lvl6; req: Endurance 5; ranks: 1
Effects: While drinking unrefined water you receive 50% less radiation
Additional info: Dreadful idea for a perk. I'm sure that you won't have any problems collecting enough stimpacks and even if you drink bad water by mistake you can always use RadAway to fight off the radiation.
BLOODY MESS - lvl6; ranks: 1
Effects: Increased damage made by all of kinds of weapons by 5%, bloody executions
Additional info: You may be interested in seeing bloody executions, but other than that it's not a good perk. The difference in damage dealt to your enemies is very small and you can achieve much more by making a turn last longer or simply by using better guns.
FORTUNE FINDER - lvl6; req: Luck 5; ranks: 1
Effects: You find nearly twice as much bottle caps as before
Additional info: Despite what you might think, it's not a useful perk, because you won't have major problems with money in the game. Spend your point on something more interesting.
GUNSLINGER - lvl6; ranks: 1
Effects: Improved accuracy while using V.A.T.S. system and a one-handed weapon
Additional info: It's not easy to make a decision whether this is a useful perk or not. You shouldn't waste perk points if you only have standard guns in your disposal. If you've managed to find a unique weapon of that kind you may consider choosing it. Notice that it doesn't have to be a pistol. You can also use this perk with submachine guns and sawed-off shotguns.
TOUGHNESS - lvl6; req: Endurance 5; ranks: 1
Effects: Improved damage resistance by10% (no more than 85% total)
Additional: A very interesting perk. You may find it useful early during the course of the game, however it'll become less useful when you obtain one of the power armors. Still you should consider spending a single point on it - maybe not right away but after reaching level 7-8.
IMPARTIAL MEDIATION - lvl8; req: Charisma 5; ranks: 1
Effects: Speech increased by 30 points, however only if you're playing as a neutral character
Additional: I guess the description says everything you need to know. Consider spending a point on this perk only if you: a) plan on winning a lot of speech challenges b) plan on playing as a neutral character. Prevent your actions from making you a good or a bad person, because you'll automatically lose all bonuses provided by this perk.
COMMANDO - lvl8; ranks: 1
Effects: Improved accuracy while using V.A.T.S. system and a rifle.
Additional info: This is a much more interesting perk than Gunslinger, mostly because rifles are more powerful and you'll be using them almost all the time. Improved accuracy will allow you to go for more headshots. You should also know that the bonus applies to all kinds of rifles, including plasma rifles!
STRONG BACK - lvl8; req: Strength 5, Endurance 5; ranks: 1
Effects: Maximum encumberance increased by 22kg
Additional info: I wouldn't advise to spend any points on this perk, because the limits are very high, even if you only gave 5-6 points to Strength. It's best to leave unwanted items at your home or to sell them.
RAD RESISTANCE - lvl8; req: Endurance 5; ranks: 1
Effects: Increased radiation resistance by 25%
Additional info: This is a very unpractical perk, because you can achieve similar effects by using Rad-X or by wearing a protective suit. Fighting off the effects of radiation is also very easy and relatively cheap.