RS Means - they have lots of estimating/costing information corraled for many different industries, including time to plant certain kinds of shrubs, trees, paver installs, etc. It sets a standard by which you should be able to begin pricing work without having detailed info on your people/crews. Of course, if yours are much slower, it could be a problem.
Their website is here:
www.rsmeans.com
I've used the Site Work and Landscape Cost Data book a few times in a pinch, but I need to start cracking down on that a lot more. The Landscape Estimating book looks like it'll be my next purchase.
For your daily sheet, what would you have them fill out? Would you have a sample you'd be willing to post (or email to me and I'll post it)?