What would be the best adapter to use?Would it be necessary to go to a Leica adapter first then Leica to Canon?

First question - do you really want to adapt Minolta MD to Canon? I can only think of a very small handful of lenses that are worth the time... Certainly don't even think about any of the zooms or even the standard primes

Going from memory a bit now, but the Canon mount has a shorter registration distance than Minolta MD, which means to mount an MD lens on a Canon you have to ram it inside the Canon - by about half a mm. Obviously not going to happen, so you either use an adaptor with a glass element - further degrading your 1960s optics, or you convert the lens itself.

If you've got one of the worthwhile lenses then you'll tend to find the conversion is covered individually - the alt lenses forum at Fred Miranda is a great resource. By far the most popular lenses to convert from MD mount are the f1.2s - either 50 or 58mm in their various incarnations. Also of note are the T&Ss, a couple of the tele-primes or the VFC lenses. All of these should be covered individually over on the Fred Miranda forum and you might even be able to pay a fee for someone to do it for you.

If you're looking at converting say a 50mm f1.4 my advice is not to bother. Just not worth the cost and compromises for what you get out of it. In fact, having owned, converted and sold a 58mm f1.2 MC Rokkor, my advice is not to bother with that either, but some people like it.