I assume, from your other posts, that you're playing a conjuror (or will be one when you reach 20).
My summoner is just a baby, so I don't have much advice from experience. However, in the "solo capabilities of a mage" thread on this forum, someone gave you a link to a page about adept IIIs. That same page has a list of the training options and recommendations for a conjuror, with explanations of what they do and why or why not to take them.