Check out the coloradokayakers.com site.
Lots of newer boaters there.
Take 285 out past Conifer, just past the gas station/stripmall on the right is a brown park sign "Reynolds Park" get off there and go left under 285, follow that road and you will come to the N. Fork of the S. Platte also known as the "Foxton" run class 3-4 depending on the flows.
Turn left and go downstream till you come to the confluence of the N. Fork and S. Fork of the S. Platte this is known as the "Waterton Canyon" run class 3-4 depending on the flows.
Follow the S. Fork upstream till you see the Colo. trail bridge that is where most people take out if they are doing the whole "Deckers" Run. Keep going upstream about 3ish miles and you will see the "Chutes" section(no parking signs everywhere) 2 falls, class 3ish, easy to portage.
Keep going upstream till the dirt road stops and turns in to asphalt and from there downstream is the "Deckers" run, about 7 miles total from dirt road/asphalt to bridge takeout.
There are alot of parking areas to stop at and put in/take out.
The upper part above the Chutes is doable 65cfs and up with some scraping. The Chutes are good at 175cfs+ and the lower is ok 175cfs and up less than 175 is real shallow in some spots.
Here is the link for the flows at the Chutes