Get in touch with three shipping companies and get quotes for shipping your belongings. (Crown were very good with our stuff - good price, communication, tracking, packing and people, received in good time and no breakages) It's worth taking at least some things with you, especially for the kids, it's their stuff too.
Do be a bit ruthless - do a really good clear out of clothes and shoes, (we were seconded to Canada for a month to determine whether we could live there or not - it gets COLD, damned cold, lol), books, kitchen stuff including pots and pans. Try to look at your belongings with objective eyes - it could be a few months before your container arrives - are you going to be thinking, what the hell did I bring that for, it's well past it's use by date. If so, charity bin, sell, or tip. But if there is something you particularly love, or have a really strong sentimental attachment to, think about taking it. We have two very well travelled armchairs that have been taken from the UK to NZ, and from NZ back to the UK again.
Be aware that plugs will be different. Factor that in with appliances etc. We brought over a couple of universal plug adaptors and multiplug boards, so we didn't have to replace everything with a plug.
Check measurements of beds. If you aren't taking your beds, if the bed sizings are different in Canada, doesn't make sense to take bedding. If the bed sizings in Canada are different to here, remember that's going to make getting bedding possibly a bit of a faff over there.
If there are things you're going to need immediately, and it's going to take a while for your belongings to catch up with you, unless you have a particular attachment to them, you might want to think about getting rid of them over here, and replacing them as soon as you get there. We got off the plane, went and had lunch at Pizza Express, then went shopping for a toaster and jug. Things like that, dinner and cutlery sets, that sort of thing. It depends on where you're staying when you get there, and how long for. We spent a month in an AirBnB when we first arrived in the UK, which was a helpful breather time for getting the stuff together for when we went into a rental.
If there are foods that are the taste of home to you, or wine or beer, check the legalities and duty/customs requirements and think about putting some of those into your container as well. We brought three cases of wine over, that we knew we couldn't get over here, that we love. Ditto chocolate, softdrink etc, that we can break into whenever we get excessively homesick. Also good for stocking stuffers, lol!
Hope this helps.