Many patent agents are also lawyers, but they don't need to be. Patent agents are often people with a technical background, often but not always with advanced degrees in particular sciences or engineering. Depending on the field, the higher the education necessary; in pharmaceuticals, for example, it's not uncommon to find PhD-level patent agents.
The process for becoming a patent agent is to write an exam. This exam is very challenging. The last numbers I saw for the pass rate across Canada were from 2010, when the pass rate was between 10% and 12%. Many people have to take the exam several times before they are successful. In terms of preparation for this exam, the most preparation that's really available through CIPO is through past exams posted online.
With regard to training courses available, IPIC—I believe you had someone here earlier this spring—offers a training course, but it's only offered in the Ottawa region. There might be one in Vancouver now. If you're coming from Atlantic Canada, you have to travel to that. It's not an inexpensive course.