Help!!!New Mac computer want work well with active rain

I had to finally get a new computer, my 10 year old Dell finally died from two many viruses. My new problem is the Mac we bought isn't working well with blogs. If I drag a picture It shows it excepted it then It appears on the blog page as a question work in a box. This is time consuming and a big annoyance! What am I doing wrong? It does not run off windows it uses Iwork. If any one uses Mac and has any pointers for me please let me know. I 'd love to know more , and would love and secret things to make my life work better with this new computer!! Any program I should consider using. i was told the Mac doesn't get viruses like the regular computers, that is why we decided to get one, my old one got a new one all the time. Thanks for sharing, I'd really love any help I can get!!