About the Mountain
–Current Conditions (NOAA Forecast)
–College of the Siskiyous Mount Shasta Companion
Administrative
–Shasta-Trinity National Forest
Blogs
–Crest, Cliff And Canyon (not about Mount Shasta but it is my favorite outdoor photography site.)
–WanderingYuncks (great hiking site that focuses mostly on Oregon, but with some California and Washington too.)
Hiking Groups
–Mount Shasta Trail Association
Other Hiking Sites I Like
–HikeOregon (similar to HikeMtShasta in many ways, focused on the northern Oregon Cascades.)
–Less Traveled Northwest (awesome site highlighting eastern Oregon and Washington. Many destinations aren’t too far from Mount Shasta)
Other Stuff
–Summitpost (awesome site devoted to mountains and the place where Hikemtshasta got its start)
–TrailGroove (a great, free online hiking magazine)
–Lists Of John (everything you want to know about mountains’ height, prominence etc. Great for highpointers. Don’t get addicted.)
Hike Mt. Shasta 
Do you guide in the area?
I don’t. I have thought about but I have to get a permit from the Forest Service and I have not done so yet.