Adding an image gallery to my website?

[baviqua]

I'm planning on adding some photos to my web site. I only know some basic html, css, and php. I'm wondering if I simply add the pictures using the <img src=.... command will I have any compatibility issues? I'm using a css template, and I'd be using width and height commands in the html to re-size the image to fit in the main content div. Any recommendations are welcome, keep in mind that I am very new at all three languages. Also, its meant to be very simple, I'm mostly concerned with any browser compatibility issues. Thanks