Mine's a bit more complex, so this'll be a bit long. The basic concept is that weapons can have more than one Proficiency Group (if it has more than one it's an exotic weapon).
All Proficiency Groups fall into three categories: Simple, Martial, Exotic.
Simple and Martial groups go like this:
Untrained: -4 to attack with all weapons in the category
Partial: +0 to attack with one weapon in the category, -2 to all others
Full: +0 to attack with all weapons in the category
Expert: +1 to attack with all weapons in the category
Master: +2 to attack and +1 damage with all weapons in the category
(Expert replaces Weapon Focus, Master is a new one)
Exotic groups go like this:
Untrained: Exotic benefits do not apply
Full: Exotic benefits apply to all weapons in the category
Expert: +1 to attack with all weapons in the category, in addition to Full
(These replace the old EWPs)
This means that if you pick up a Two-Bladed Sword and don't have the Exotic proficiency, you can still use it as a single-end weapon.
Also, Weapon Specialization and Improved Critical can be taken by any class, although they require Expert proficiency (certain classes only require Full; the heavy fighter-types only need Full for WS, the finesse types need Full for IC)
The longer list:
(Notations: each asterisk means an Exotic group. A ^ means it's a double weapon with two different ends; each end will use a different Simple/Martial proficiency)
SIMPLE CATEGORIES
Natural Weapon: Unarmed Attacks (including the improved Monk attacks), Natural Weapons, Gauntlets
Light Piercing: Dagger, Punching Dagger, Spiked Gauntlet, Siangham/Halfling Siangham*, Bladed Gauntlet
Light Slashing: Sickle, Kama/Halfling Kama*, Kukri*, Kusari-Gama^**
Light Bludgeoning: Light Mace, Heavy Mace, Morningstar, Club, Quarterstaff*, Nunchaku/Halfling Nunchaku*
Light Spear: Shortspear, Halfspear
Crossbow: Light Crossbow, Heavy Crossbow, Repeating Crossbow*, Hand Crossbow*
Light Ranged: Dart, Sling, Javelin, Shuriken*, Blowgun
MARTIAL CATEGORIES
Medium Piercing: Short Sword, Rapier, Light Lance, Elvish Thinblade*, Dwarven Urgrosh*^
Medium Slashing: Long Sword, Scimitar, Two-Headed Sword*, Wakizashi**, Mercurial Longsword*
Medium Chopping: Throwing Axe, Handaxe, Battleaxe, Light Pick, Heavy Pick, Gnome Hooked Hammer*^
Medium Bludgeoning: Sap, Light Hammer, Warhammer, Gnome Hooked Hammer*^, Greatclub
Heavy Slashing: Greatsword, Falchion, Bastard Sword*, Khopesh*, Katana**, Fullblade*, Mercurial Greatsword*, Daikatana*
Heavy Chopping: Greataxe, Halberd, Scythe, Dwarven Waraxe*, Dwarven Urgrosh*,^ Orc Double Axe*
Heavy Piercing: Longspear, Glaive, Guisarme, Ranseur, Trident, Heavy Lance, Naginata*
Bow: Shortbow, Composite Shortbow, Longbow, Composite Longbow
Flexible Weapon: Light Flail, Heavy Flail, Dire Flail*, Spiked Chain*, Whip*, Net*, Kusari-gama^**
EXOTIC CATEGORIES
Double Weapon: Quarterstaff, Two-Headed Sword, Dire Flail, Gnome Hooked Hammer, Dwarven Urgrosh, Orc Double Axe, Kusari-gama, Dire Flail
Exotic Benefit: The weapon may be used as a double weapon with all the normal rules and modifiers, although nonproficiency in the Simple/Martial groups carries the usual penalties. A user without this proficiency can use the weapon as a single weapon with no penalty or as a double weapon with a -4 nonproficiency penalty.
Heavy Weapon: Bastard Sword, Dwarven Waraxe, Elvish Thinblade, Fullblade, Khopesh, Katana, Wakizashi
Normal: The weapon is a light weapon for any wielder of larger size than the weapon, may be used one-handed by any wielder of the same size, or two-handed by any wielder one size smaller. (Note that the Bastard Sword, Dwarven Waraxe, and Elvish Thinblade have been erratad to be Large weapons, while the Fullblade has been changed to Huge.)
Exotic Benefit: The weapon is wielded as if it were one size smaller. It becomes a light weapon for a user of the same size, may be used one-handed by a user one size smaller than the weapon, or used two-handed by a user two sizes smaller. (Note that this allows for a Halfling to use a Bastard Sword, or a Human to use a Fullblade.)
Exotic Ranged: Repeating Crossbow, Hand Crossbow, Shuriken
Exotic Benefit: Hand Crossbows may be reloaded as a move-equivalent action; Repeating Crossbows may use the full-attack option; up to three Shuriken may be thrown as one attack.
Entangling Weapon: Whip, Net, Spiked Chain, Kusari-gama
Exotic Benefit: Whips, Spiked Chains, and Kusari-gamas gain a +2 bonus to opposed attack rolls to disarm an opponent and may make trip attacks; Nets take two rounds to fold for re-use (instead of four) and their Escape Artist DC increases from 15 to 20.
Monk Weapon: Nunchaku, Siangham, Kama, Halfling Nunchaku/Siangham/Kama
Exotic Benefit: When used by a character with an improved Base Attack Bonus progression for unarmed attacks, the wielder may use the unarmed progression.
Fine Weapon: Kukri, Wakizashi, Katana, Daikatana, Naginata
All weapons in this category must be of ?masterwork? quality (Fine Steel or better) regardless of proficiency.
Exotic Benefit: The critical threat range increases by 1; the Naginata becomes 19-20/x3, while the others become 18-20/x2. This is taken into account before any other factors, such as Keen or Improved Critical.
Flowing Weapon: Mercurial Longsword, Mercurial Greatsword
Exotic Benefit: The user receives a +4 competence bonus to critical hit confirmation rolls. Also, unlike other exotic groups, nonproficient users get a -4 attack penalty.
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Anyway, so classes translate pretty easily. All classes get Full proficiency in all Simple groups IMC. Bards pick any one Martial group, all Clerics get Partial with their deity's favored weapon, Monks get the Monk Weapon exotic. Most of the other fighter-types get Full in all the Martial groups.
Some of the weapons listed have different stats than listed in PHB/DMG/S&F (like the Kukri and Katana)
