Well, firstly, I recommend you get yourself the Advance Version of FFV and find the DS remake of FFIII (the REAL FFIII: not the one with Terra and Celes and Gestahl all those other guys) to start off.
Also, if you want the first two games, get Final Fantasy I & II: Dawn of Souls for the GBA (it's a collection of the first two FF games from Japan and currently the only legal way to play the real FFII). I have no advice on them since I haven't played them yet, but if you ever need help just look up HCBailly on YouTube: heck, for any help you'd ever need in a FF game from I-IX, just go to HCBailly.
And if you want to get into FFVI (the one with Locke, Strago, and Kefka) I recommend you pick up the SNES version along with an SNES or wait until the 3DS version is released. SNES version has cruddiest translation and the most bugs, sure, but it's better than the loading time of the Anthology version and the screwed up music of the GBA version (although FFVI is probably coming to the 3DS so you may want to wait for that) and it's actually kind of endearing once you get used to it.
FFV Advance I recommend you get into the habit of grinding regularly or setting up battles strategically (like having Bartz be on Samurai until he learns Iainuki/Slash and then put him on the Ranger in the back rown with the Herme's Sandles and have him slash everything to death).
And don't judge a Job by it's face value either: Jobs like the Chemist and Blue Mage are extremely useful if you know how to use them (ESPECIALLY the Chemist: Maiden's Kiss + Turtle Shell = Massive Damage and some delicious HP recovery). If you ever get stuck or need help with something, look up HCBailly on YouTube (he covered FFV EXTREMELY well [but be warned, there's some mature humor and swearing in some of his videos] and completely annhilated the game more or less).
As for FFIII, all you really have to do is set one physical tank for most of the game (the Knight works extremely well for this and the Warrior earlier on works too), two Mages (preferrably of the White/Black or Devout/Magus variety [Devout is a more powerful version of the White Mage and Magus is the more powerful version of the Black Mage]) and one physical house (the Monk and later the Black Belt work very well for that, but make sure to keep them barefisted for most of the game since they fight better without weapons around the time they reach level 10).
And don't worry about having your Warrior/Knight double wield swords: the boost from Shields is negligable and the nearly doubled (most of the time) attack power more than makes up for it.
Also, make sure to put guys like your Mages in the Back Row (they take less physical damage that way and their Magic isn't affected, and trust me, with how cruddy their Defense can be, they need all the help they can get) but take care to keep your physical attackers in the front row (they take more physical damage that way, but with how good their Defense is they can handle it and they also deal more physical damage that way than in the back row). Again, if you ever need any more help than that, look up HCBailly on YouTube.
Then, you could buy FFVI (III in the US) either for virtual console or GBA. It is a SNES game, and it is also considered to be one of the best FFs.
FFVI isn't available on the VC if I recall correctly. But yeah, he should definately go for FFVI eventually (SNES version is best, but any version is good).