How do I protect myself when offering software and training?

I plan to sell software and add "the software comes with no warranty and should not be held liable for loss of data" and etc. I also plan to offer on-site training for the software. 'Support' will either be through a community forum or non existent (but there will be a solid manual). Perhaps I'll have phone support which can be bought, but I don't think I will.

How do I protect myself or the company from being sued? I cant think of any reason why I would, but that won't stop anyone from trying if something happens.

I never heard of a lawsuit over training, and I don't think refunds are a big deal (although traveling expenses may be). Do I have anything to worry about in my simple case? I'm planning a sole proprietorship, but even as a corporation I wouldn't want to be sued into the ground.

Note: My location is in Ontario, but I plan to train anywhere in Canada and the US.

Nothing can stop you from getting sued. Companies get sued for idiotic reasons all the time, no matter what the contract said.

That said... something someone told me when I started Fog Creek Software was very helpful: "Deep pockets don't sue shallow pockets." Nobody's going to sue you if you don't have money, with the possible exception of the RIAA. It's ex-tremely rare for large/rich companies to sue small companies. Essentially, make sure your contracts are good (have a lawyer review them) and actually state what you intend, and then stop worrying about it.

This advice worked fine for ten years. The first time we got sued was after we raised $6 million in venture capital, and hiring the best lawyer in town was a rounding error.

Make your terms of service clear and fair. Offer reasonable but explicitly limited credits if people have issues with your software.

Treat your customers fairly and listen to them. Malpractice insurance companies are now sending doctors to school to learn how to listen - it turns out that a big driver in malpractice suits is "the doctor never listened to my concerns and questions" and when people feel like the doctor cared - even in the event of a mistake - they're much less likely to sue.