Hello floyd,
Whatever you're asking has been covered numerous times in this forum. However, I will try my best to point you in the correct direction. Please be aware though, that I am not in the CF. I am just an applicant who has been in the process for nearly three years.
1. Interview - nobody here or in the RC will tell you the exact questions before you're interviewed. That being said, the CF interview is nothing different than one you would apprear for a civilian job. They expect you to know the organization (the CF), the corps you intend to be a part of, the occupation and they would like you to know your own abilities and drawbacks. I have appeared for three interviews - the first one lasted an hour, the second time it was for over three hours and the third time was about an hour. A single Military Career Counsellor could interview you, or there can be two. I've been in both situations. One tip for the interview - if you have any letters of recommendation from teachers, coaches or employers, I suggest that you take these along. Now say in the interview, you were asked about a time when you displayed a certain quality. If you have a letter which speaks of you doing something similar in glowing words, and you cited the example and showed the letter. Imagine the effect that will have!
2. CFAT - Take a look at the practice exam on the CF website. I bought books specifically dedicated to number sequences, spatial ability, etc. It was a bit of an investment, but for me the time and money spent in preparation was totally worthwhile.
3. Medical - This is composed of three parts. The first two parts happen in the RC and the third is done at the CF Recruiting Group HQ. Nothing really to get stressed out about, because there's really nothing that you can do to prepare. If you're medically fit, then you have no cause to worry. Oh yes, if you wear prescription glasses, it is recommended that you bring the prescription. The medical exam is essentially answering a number of questions about your medical history, checking your vitals, hearing, sight, height, weight, etc. If the staff conducting the medical find you to meet the CF standards for the occupation, they will recommend you. The final okay is given by HQ.
4. Physical - Regular force applicants do not have to appear for a physical. That being said, it'll be a good idea to be aware of the CF fitness standards and start a training regime keeping this in mind.
I suggest going over the CF website and contacting the RC. You will find more comprehensive information from these sources.
All the best,
ABG.