Best Jobs to Master for your Characters
The main goal in Final Fantasy V is to master as many jobs as you possibly can because doing so will allow you to carry over Innate Abilities & Stat Improvements to the Freelancer Job. You start out the game as a Freelancer but the job is almost useless because it has no special abilities or stat bonuses. Every Job you master gives you stat increases and sometimes even innate abilities that carry over into your Freelancer job.
This basically means that the way Final Fantasy V is intended to be played is for you to cycle through Jobs throughout the game, eventually mastering them so that at the end of the game you use the Freelancer Job. It's recommended that you figure out your character's roles early on and what abilities you want to use on them. Then you know which Jobs you will want to Master for each character for their innate bonuses.
My Job Choices:
Bartz: Knight (Stat Bonuses), Monk (Stat Bonuses), Ninja (Dual Weild), Berserker (Stat Bonuses), Hunter (!XAttack/Sshot), White Mage (!White and Stat Bonuses), Geomancer (Stat Bonuses), Bard (Stat Bonuses)
Lenna: Monk (Stat Bonuses), White Mage (!White), Black Mage (Stat Bonuses), Summoner (!Summon), Red Mage (!Red x2/Dualcast), Bard (Stat Bonuses)
Galuf/Krile: Knight (Stat Bonuses), Monk (Stat Bonuses), Ninja (Dual Weild), Hunter (!Xattack/Sshot), White Mage (!White and Stat Bonuses), Time Mage (!Time), Bard (Stat Bonuses)
Faris: Knight (Stat Bonuses), Monk (Stat Bonuses), Thief (Stat Bonuses), Berserker (Stat Bonuses), Sorcerer/Mystic Knight (Stat Bonuses), White Mage (!White), Bard (Stat Bonuses)
It doesn't really matter what order you decide to level up these jobs in so long as you make sure to have at least two people in your party at all times with !White. A side note, on the FF Anthology version of the game (Ps1) the Red Mage class doesn't get Dualcast - he gets a crappy ability called Redx2 which limits him to casting two Red Mage spells - NOT two spells.
Let's take a look at the final set of skills I decided to teach to all of them. These are the skills that I chose on each of my characters on World 3 once I maxed out all of the jobs that I wanted to level up.
My Skill Choices:
Bartz (Primary DPS) Skill Choices: !XAttack/Shot and !White
Lenna (Secondary Healer/Magic DPS) Skill Choices: !Redx2(Dualcast) and !Summon for the majority of the game. !White and !Summon World 3 and beyond.
Galuf/Krile (Secondary DPS/Support Magic) Skill Choices: !XAttack/Sshot and !Time.
Faris (Primary Healer) Skill Choices: !White and !Mug (Mug can be subsituted for anything else you'd like instead).
In closing, any character you plan to have as a melee damage dealer you'll want to learn !Xattack (Hunter) on and Dual Weild (Ninja) because it'll allow you to put out usually double or triple the amount of damage you can do in one attack round. I also very strongly recommend you learn !White on every single character of your team because you never know what's going to happen and it's best if you're well prepared for any battle. You don't always need to assign !White to every character but it's worth knowing.
!Time is worth learning on one character that you want for Haste, Warp, Teleport, Float and other very useful abilities. Finally the character you choose that'll specialize in dealing damage with magic abilities you should teach !Summon to. As I said at the start of this guide, this is mostly my opinion on what to do with your classes in FFV and I made this guide for people who are too lazy to learn the Job system themselves and just want to be told what one of the best combinations are. All that said, I strongly recommend you do learn the Job system yourself since it's one of the best systems in any Final Fantasy game to date.