The North Buttress is a fun and worthwhile alpine route up one of the more aesthetic peaks in the San Juans. Midsummer would be the ideal time to climb the route, since the rock should be dry and snow free and the snowfield at the base of the buttress will have receded somewhat. Spring and fall could provide a more full-on alpine experience with the potential for ice and mixed climbing on the route.
Once you're at the base of the buttress, climb 5.6 rock until you're basically following a ridge (4th and low 5th) up the path of least resistance. Continue climbing the ridge until you gain a notch below the summit (the top of the Snake Couloir). From here, it is the same finishing pitch (5.6 or so) to the summit.
Descend the main trail to Lavender Col and drop down the scree field below Kismet and back to Blaine Basin.
Park at the Blue Lakes/Blaine Basin trailhead. Follow the trail to Blaine Basin and up to the moraine which sits below the North Face of Sneffels. Ascend the snowfield to the buttress which is between the NE and NW snow couloirs. This is the North Buttress, directly left of the Snake Couloir route. Once at the base of the buttress, the best place to start is fairly obvious, and there are some ancient pins at the start.
A single set of cams and stoppers. Depending on the season, an ice axe and/or crampons could be needed to ascend the snowfield at the base of the buttress.