You should check out french.about.com, to get a real handle on this.
As a rule of thumb,
aimer used with a person means to love,
aimer used with an object means to like.
But this is not the whole picture - check out the web link I have mentioned by clicking on the light gray word. To get back here - use your return key in your browser.
Why does the correction say that it should be "like" because "aimer means love when applied to people or pets" when a turtle is exactly that -- a pet?