...there are a number of methods to remove a background from an image, in your case and to keep things simple, use the pen tool to create a path around your object...
...with this path, you can make it a clipping path by saving the path and then via the flyout menu in the paths palette select clipping path, flatness can be left blank...
...or...
...with this path found in the paths palette, hold command/control above your created path in the paths palette, this will activate a selection. Go to your layers palette so you can see what happens in the final result...
...with the selection still active, go to 'select > inverse', this will select the area to delete. The background colour swatch plays a part when you hit delete, if you want white then make the background swatch white (found at the foot of the tools palette)...
...if you want a transparent background, then double click the background layer and click ok, this will now be named layer zero. If you hit delete now you will see the checkerboard background, meaning transparent...
...if you want to give your selection a softer edge you can either go to 'select > feather' and experiment with the input field, click ok and hit delete, if not happy, then go back a few steps in your history palette and try again...
...another method is to create a layer mask, with your active inverted selection hold the alt/option key and click on the layer mask icon at the foot of the layers palette, this will be created next to the icon in the layers palette. Black is hiding and white is showing the image...
...you can blur this layer mask using the gaussian blur command to soften the edges if you wish. Once happy flatten the image via the flyout menu in the layers palette, this will flatten to white...
: )
Andrew