I am looking to do this cake:

http://www.cutest-baby-shower-ideas.com/baby-boy-animal-cake.html

(but only one layer)

Instead of covering my cake with fondant, I would like to ice it in buttercream, but do the cutouts in fondant.

What do I need to know? Should I make the cutouts today and let them dry until say Thursday, and then put them on the cake?

Or should I cut them out and immediately put them on the cake, on Thursday?

Will they attach straight to the buttercream or do I need to put something on to attach them to?

Thanks in advance for all the help, this is my first venture into fondant!

I generally do my cut outs as I am putting them on the cake. If you don't need them to curve around the edges or sides, you can do them early and let them dry.

You can use a little buttercream, piping gel, vanilla, or anything else wet to attach them. Just use a little bit though.

I Agree, I let my cake cool so it don't get damaged as i decorate it but i do put decorations right after i cut them

Thanks. Never thought about using vanilla.

I always do my cut outs ahead of time, I like to have everything ready to go. They firm up a bit and are easier to pick up and place on the cake. I have cut them out and put in zip lock bags, and they stay soft, so they can be curved if need be.