google should work. Add as many points as you want. zoom in any place you want. it can be as detailed or generic as you want. It is probably the best you can get for free.
However, I think MSS&T will work better for you and do exactly what you want. Adjust your speed, schedule departures and even add layovers. Once you adjust the speed in options, the timing is also pretty acurate. Plus, once the route is sorted out, you can run it on the laptop and let it provide the turn by turn direction. Either buy it with the GPS dongle, or attach any NEMA compatible GSP device to the laptop.
Last trip out west in 2005, I used it and had about 60 stops to get the route planned out right. Then I got out on the road and updated each night as my trip varied due to side trips, heh what's down that route, look over there, etc. Made it nice for reworking my route on the fly.
Another nice feature with the MSS&T is you can add push pins for places you want to visit, data from other programs, etc and then simply add or delete them from your route. I don't buy many programs, but it is one of the few I have bought and updated several times.