Why Saturday's 3.5 hour workshop wasn't nearly long enough...

If you really intend to complete T2125's, I'd recommend first of all, that you've read the Income Tax Act.  You can find a free copy on the Justice Minister's web site, www.justice.gc.ca or at www.canlii.org or you can buy a copy with annotations and indexes to help you find stuff from either Carswell Thompson or CCH. An annotated copy costs about $125 and they update them several times per year.

Then I'd recommend you read the CCH Preparing Your Income Tax Returns latest edition every year to get what you can't get from the law, which is an interpretation. That book costs about $100

Then, I'd recommend you read the CRA website from cover to cover - start with the Site Map. That's free but very frustrating as the topics are sort of dealt with like you are cross dressing, you'll find bits of information all over the place without the connectivity to really figure it out without years of pouring over the IT Bulletins, the IT News and IC's. plus the Income Tax Act, but I already said that above.

And then, after all that, here's a 30 hour course you might appreciate...that delves into the fine points of the form completion offered by someone who does a great job of delving into detail.

Evelyn Jacks course on Proprietorships

and oh yes, then you still have to figure out how to make the tax software work, and check your work to make sure you didn't create one too many T2125's and enter everything twice, or even three times or the vehicles on one schedule that links to one T2125, and the home office on another, and the assets on a third, and the operations on a fourth...

Just kidding you think? I had to fix someone's return for several years back because of exactly this prior preparer error.

If you aren't at this level, and just want to learn how to prepare a basic tax return, there's always my Student WorkBook with videos and case studies to get you started. It's under the My Projects tab on my website.

Start now! Please don't wait until next April though, because even that takes a few hours to work your way thru.