I'd recommend that you drop in to REI or your LBS and pick up the Falcon Guide. There are some flatter routes mentioned in there. The Bluffdale/Herriman ride is flat. There's also a loop that starts near Gardner Village and takes you south around the prison. The only real hill is by the prison, but you are rewarded with a nice downhill into Bluffdale.

There are some nice flat rides up in Park City for when the air gets too yucky in the valley in the summer.

It's nice to hear of another SLC cyclist on TE!

Alex