First trip across country... VA to CA!

[XXJOEYXXEB]

Hi guys,
I'm new here, so let me start by saying hi. This September my girlfriend and I will be driving back to school in San Luis Obispo, CA from her place in Fairfax, VA. We are gonig to take just under a week, hopefully 6 days. I'm just trying to find out where we should stay, and where we should visit. I did a mapuest and it suggests we take I-40 W. I am thinking about stopping at Fort Knox area for a nigth and day. Anything else would be greatly appreciated! Keep in touch!
Thanks,
Joe

[XXJOEYXXEB]

OK, it might end up us driving from Cape Cod, MA to CA... through I-90, I-80, and I-70, then to I-15. If anyone has information on either routes, let me know! thanks!