Creating image background transparency

Hey, thanks for taking the time to read this.

Here is my website: Hardgainer Workout Routine

Now, unless you look at the main logo and “New Whey Liquid Protein” tube on the top right of my homepage, you might not be able to tell that they aren’t flush with the background. In other words, I added the existing background of my website to the images and stuck em in like that.

However, I was wondering if there was a way to make the background on the images transparent, possibly in Photoshop? I mean, I know how to cut out the images so that the checkered (transparency) is the only thing that shows, but everytime I save the images, it adds a white background.

Is this possible? Any help is appreciated. Thanks.