Final Fantasy VIII - Weapons

In Final Fantasy VIII you upgrade character's weapons by taking the right items and gil to a tool shop.  Each character has at least three upgrades, and you can skip right to the final one if you like, without passing through the inbetween steps.  Squall's limit breaks are linked to his weapons, but, again, you can skip right to the last weapon and get all the limits inbetween automatically.

Throughout the game, you'll find various Weapon Monthly magazines, which will detail the items needed for the upgrades.  You don't need to have the magazines on hand to upgrade the weapons.

You'll find the magazines in the following locations;

Issue	Location
March	Automatically.
April	Squall's desk, when he has a single room at Balamb Garden.
May	Deling sewers.
June	automatically.
July	Training centre, disc 3, left side.
August	Five steps south of Trabia Garden's gargoyle statue.
1st	Found by Laguna in the Esthar lab.

The character's best weapons and the items required are as follows;

Character	Weapon	Requires
Squall	Lionheart	Adamantine x 1 Dragon Fang x 4 Pulse Ammo x 12
Quistis	Save the Queen	Malboro Tentacle x 2 Sharp Spike x 4 Energy Crystal x 4
Zell	Ehrgeiz	Adamantine x 1 Dragon Skin x 4 Fury Fragment x1
Selphie	Strange Vision	Adamantine x 1 Star Fragment x 3 Curse Spike x 2
Rinoa	Shooting Star	Windmill x 2 Force Armlet x 1 Energy Crystal x 2
Irvine	Exeter	Dino Bone x 2 Moon Stone x 1 Star Fragment x 2 Screw x 18

...which gives you the following shopping list.

Item	Where?
Adamantine x 3	Mug (1) from BGH251F2 (boss) at FH. Dropped by Adamantoise at level 30 plus (Haspberry Plains beach, near Timber) Card Mod: Minotaur = 10 Adamantines.
Curse Spike x 2	Dropped by high level Creeps (Deling City Sewers). Card Mod: Tri-Face (Galbadia Garden).
Dino Bone x 2	Dropped by low-level T-Rexaurs (Balamb Forests, Training Centre) Card Mod: 2 T-Rexaurs = 1 Dino Bone
Dragon Fang x 4	Dropped by Blue Dragons (Near Trabia, in the Forests) Dropped by T-Rexaurs (level 20-29).
Dragon Skin x 4	Dropped by Anacondaurs at level 30+
Energy Crystal x 4	Card Mod: 10 Elnoyle = 1 Energy Crystal, or dropped by Elnyoles over level 30.
Force Armlet x 1	Won from Edea on Disc 2, as long as you don't mug. Can be bought from RinRin's shop in Esthar if you have Tonberries Familiar ability. Rare drop from high level Ochus.
Fury Fragment x 1	Card Mod: 4 Blue Dragon = 1 Fury Fragment
Malboro Tentacle x 2	Card Mod: 4 Malboros card = 1 Malboro Tentacle
Moon Stone	Dropped by Elnoyles, Imps, and Toramas in Esthar.
Pulse Ammo x 12	Ammo-RF: 1 Energy Crystal = 10 Pulse Ammo, or 1 Laser Cannon = 5 Pulse Ammo.  Laser Cannons are dropped by Elastoids over level 20, which can be found in Centra, during the Laguna sequence.
Screw x 18	Dropped by Geezards (near Timber and Galbadia) Card Mod: 1 Geezard = 5 screws
Sharp Spike x 4	Card Mod: 1 Grand Mantis = 1 Sharp Spike
Star Fragment x 5	Card Mod: 3 Iron Giants = 1 Star Fragment You can find and card Iron Giants in Esthar after the Lunar Cry. Or, mug from T-Rexaurs at level 30+.
Windmill x 2	Card Mod: 1 Abyss Worm = 1 Windmill.  You can find (and Card) Abyss Worms in deserts near Galbadia.

It's fully possibly to have the best weapons on disc one if you level and play cards appropriately. If you're playing a low level game, it's still possible, but you will have to Mod a few rare cards. If you do, you can get them back on disc 4 from the Card Queen and the CC Club aboard the Ragnarok. This is true for all cards except the PuPu card.

If you wait till later, using Tonberry's level up skill will help with some of the items which are most easily obtained from high level drops.