Finding it very difficult to upload images from my desktop and insert into post

Sorry, I thought I was adding to the thread that hognose had started. I too found adding you tube video and images extremely difficult and hope that you can give me an instruction over this, as many of my websites are advertising for Amazon and I need to use product images and so far I haven’t succeeded in getting any to upload. As a mac user I don’t have a right mouse click and don’t know where to get the URL for the image. I usually slide the image off the Amazon page onto my desktop and before had no problem uploading it from there onto my webpage in the position I wanted it to display.

I finally did succeed in getting a you tube video to embed into http://healthandfitness4you.net, but not sure I will remember how to do it again. I do hope you can help and give me an instruction on how to do this as I have spent an entire afternoon struggling without success.