I need to do a "Angel" themed birthday cake for a grandmother who loves angels and have no idea where to start so I thought I'd turn to all the experts on CC -- any help would be greatly appreciated

Do you need one or two tiers? Either way, I'm seeing a sky blue cake with clouds of the cake (and/or tiers); then you could make gumpaste or fondant angels and have them on the clouds. They can be doing different things (if you make multiple angels), maybe looking over the side of the cake and the board be the world, or just earth in general. Maybe hands outstretched, or in poses of angels she collects.

Thank you so much for taking the time to respond-- that's a great idea - they just want one tier.

I think it can still work with one tier. It doesn't need more than that. I was just curious when I asked that question. I would love to hear and see what you end up doing for her. Have fun.