It's definitely a good idea to try the route on the Weekend. You might even want to do that twice. Then you will "tweak" your route as you start riding regularly. I use http://ridewithgps.com/ to plan my bike routes (they use Google data). Then I compare them against Google Earth (although some of the satellite images are out of date as I have learned the hard way, LOL), paper maps (if I have any) and search the web for others who might be using these routes, not necessarily for commute but even for weekend or club rides.

Then I would create a track and load it to my GPS, but I would still make notes, create a paper cue sheet and bring a map along (just in case). I'd also bring a pad a pen along with me so I can take notes about possible changes to the route.