Repot Dendrobium
 

I have a dend. I am not certain how to repot. I have attached a crude photo. It is getting very tall. Should I try to separate? Should any pseudo bulbs be cut off? I do plan to separate the new shoots, but am unsure what to do with the mature sections.

I would strongly advise against dividing your Den. They do much better and stay healthier as a larger "colony". Leave the old ratty canes on, the plant will use up the nutrients stored in it. Repotting Dens can be tricky. They like to be pot bound so often you can use the same pot you took it out of and just put in fresh medium. I like to go up a half size in pots, especially if it's been growing well. Some Dens will sulk after repotting, and even drop leaves if they are really having a tizzy. You just have to wait them out. They eventually get over it. BTW, there was no picture attached to your post. :)