Races

• Human is always a good choice. We are humans, of course, so it's easy to understand the racial mindset, and the extra feat and skill points are always, always handy to have. Human is a solid race for any class and should always be considered.

• Warforged (Monster Manual III or Eberron Campaign Setting) can be a little fiddly, but if you understand them they can be really feel-good for a new player because they're immune to a lot of tactics that feel really un-fun to face up against. Plus, y'know, who doesn't like being a giant robot?

• Dwarf is always nice for melee concepts if he's into dwarves, and should be considered for such.

• The "Lesser Planetouched" variant on the Planetouched races (see Player's Guide to Faerun) are acceptable and relatively simple to understand, if a bit underwhelming.

Classes

There's some controversy on this subject. Some folks will tell you that you want to go with something that doesn't involve fiddly subsystems like spells, maneuvers, or vestiges. I would say that it's never too early to teach a player these invaluable aspects of 3.5. With that in mind, here's my suggestions:

• Any of the Tome of Battle classes, but especially Warblade and/or Crusader. Very feel-good melee that's difficult to build incorrectly - if you choose powers that sound cool, they are cool! Even with completely unoptimal feat choices Warblades, Swordsages and Crusaders make for dynamic and helpful contributions to any party.

• Druid takes a bit more planning and if your player has attention-span problems it might not be the choice for him, but it's worth mentioning chiefly because, well, it's Druid. He can get familiar with spellcasting, minion-mancy, melee and stealth all at once, and there's just something about the sales pitch, "Would you like to be a T-Rex that spits fireballs?" that attracts players to the idea.

• Duskblade blends spellcasting and melee with a very focused spell list and intuitive abilities. He can be a bit fiddly but, like Warforged, isn't hard to teach. You can find him in the Player's Handbook II.

• Factotum (Dungeonscape). Insert high Intelligence score, pull string, instant build. Factotums do a little bit of everything and then some. Factotum might be a good fit for your player because they're changeable and don't have to stick to the same tactics or ideas in every encounter - combat, social, mental, or magical - and all of this versatility revolves around their Intelligence score, which means that they really can't be punished by low rolls or bad point buy.

Read To Him

You should be doing this anyway because reading to kids is good for them in general, but it's really handy here. Both to encourage reading, and by mixing in stories of adventure you can let him use his imagination and foster that type of development.

Play Games With Him

You're already doing this. Keep it up! Make believe games are great, as they're pretty close to RPGs already. Board games with simple rules that kids can play are also good for learning how to follow rules.

The most important thing really is that if "games with parents" is an activity that he grew up with and likes, it'll be pretty easy when you're ready to invite him to an RPG by saying "we're going to try a different game tonight."

Play RPGs Yourself

Kids tend to internalize activities that are going on around them frequently as normal. So, if you want to introduce him to gaming later, you should try to game. If he sees people having fun doing that, he's going to ask what it is and be interested in what's going on.

You don't have to let him play right away when he asks, but it sets the stage for this being an activity that you do. (My son likes it when I roll dice, but he's too young to do it himself because he wants to eat them. One day I want to let him "help" by letting him roll for the monsters.)