I once found a Mandarin Chinese dictionary which for each character listed the ancient, the traditional and the simplified Chinese characters. For each it described its meaning and how it developed into the current form. I cannot find it or anything similar anymore. The most I can find are sites which explain radicals of each character but not actual ancient symbols and variations.
For instance, the word "eye" was shown as a pictogram resembling an eye, then into the traditional and then into 目 explaining "a simplified eye turned 90°".
I know not all characters are made this way but again, maybe it was a dictionary of radicals but it was very good.