Route 66 - CA to St. Louis

[maxm50]

Hey all,
I'm heading out of CA on I-40 headed for Columbus, Ohio next week. I'd like to take Historic Route 66, which as I understand it snakes around I-40 the whole way to St. Louis, correct? I've been going through this route 66 site and mapping it out street-by-street on Microsoft Streets and Trips, but it is taking forever to drag that darn little green line off of I-40 onto every single Rte 66 side road.

So, here's my question: If I just start off on I-40 in Barstow, CA, and follow it east, will there be signs pointing me in the direction of Rte 66 the whole way? If I get lost, I know I can always get back on I-40. Is Rte 66 well-marked enough that I don't need to plan the whole thing out beforehand?

Thanks,
Max