ok photoshop gurus.. i need your help!

i took this fantastic photo of krystal at the beach @ phillip island, i want to get it printed as big as i can (i have uploaded to my gallery if u want to have a look)
but theres something i want to do with it first.. i hope i can explain ok!

i want to put another two photos on top of this one, to the left of the pic, one under the other...

i hope someone gets what i mean!! and can help me!!!!