Probably the best site (quality images, supplied by DND so no copyright issue, usually with a full caption so you know the context, on an operation basis, with links to all three branches) is:
A site that also falls in the "safe and useful" category (usable and DND-sanctioned) is:
Of course, the various branches tend to have their own thing going on, such as Army's ...
And beyond that, even the particular brigades and fighting groups have identity sites (where you can sometimes find excellent pictures), for example ...
If you are lucky enough to be a reader of this blog who's in the Canadian Federal Government then the above links might be useful for your work.