why am i not seeing my photos on iCloud?

I was recently introduced the iCloud. I went into the Apple store and was told that by creating an account and backing everything up, to the cloud would save my things most importantly my photos.. I did this on my Iphone 4, and since then I went to iCloud.com to view what had been saved, backed up, streamed or whatever... All is there except my photos, there are icons for my contacts, calender, notes, and my email. What if anything did I do wrong? Please explain how this is supposed to work.