Hi, Niki! How exciting for you both--homeschooling can be a real adventure--your son sounds like a terrific little guy, and I'm sure you're going to have a great time together!

I have a couple of resource ideas which have worked well for us here, which I'll just toss out to see if they might grab you:

We have really liked MEP math from the University of Plymouth; the programme is fun, it's innovative, it's very challenging, and it's free: http://www.cimt.plymouth.ac.uk/projects/mep/default.htm
I gather that some topics are not taught in the same order as in US schools (?--I'm not American), but if you are not having to do any sort of testing, that will likely not be problematic.

For language arts, one of mine (the extraordinarily verbal one!) loves the Michael Clay Thompson series from Royal Fireworks Press. These books are designed for gifted classroom use, but they are very easy to use at home (they're not all full of group projects, etc.). Each level has grammar, writing, vocabulary, and poetry components.
http://www.rfwp.com/mct.php

Another one of mine, quite a different soul, has been enjoying the Junior English series from Galore Park; these aren't as creative as the MCT books, but there is still a lot of scope for depth and the pursuit of individual interests in some of the assignments.
http://www.galorepark.co.uk/parents.php?category=English

Handwriting has been a little bit of a trial around here, but the lads are making some good progress with the Getty-Dubay series.
http://allport.com/Artists.aspx

What languages are you planning?

We use "real" books (sorry, can't think what else to call them--don't mean to be offensive!) for history, science, art, and music so far, rather than curriculum-ish stuff. I have no objection to that sort of thing, obviously, but I wanted to strike a balance between a fairly programmed (albeit accelerated and compacted) approach to the 3 Rs and a lot of freedom in exploring other topics. I am also juggling three little peanuts, so that affects how we do things, too. I think your reference shelf sounds like a great idea--we make heavy use of atlases, encyclopedias, and dictionaries around here, for sure.

Mostly, we just have lots of books around. In regard to things like character building, I just try as much as possible to pick very high-quality literature for read-alouds; the Victorians, for instance, were very big on character building!

Hope that helps a little--

peace
minnie