There area a variety of image management tools available to you.  You can choose to use on-line resources such as Flickr and Picasa or off-line tools such as iPhoto, Aperture, and Photoshop Lightroom.  Below is a brief list of those you might consider.  

Some questions you might use to find the right solution for your situation:

• How much do I want to spend?
• Do I want my collection online or on my computer?
• How much description do I want to give to my images?
• Do I need to be able to manipulate my images as well as manage them?
• Do I want to easily share my information/image with others over the internet?

NOTE: This is not an endorsement for any one Digital Asset Management (DAM) solution, but a list of the products available to you.  For advice on starting a DAM project see the JISC Digital Media page Systems for Managing Digital Media Collections.