Collaboration across the pond

I'm a Grade 7 teacher in rural New Brunswick, Canada. My students (age 12-13) have laptops and as a class, we would like to collaborate with students in the UK.

I'm a new teacher and new to technology, but I would love to use wikis, Dabbleboard, VoiceThread... whatever the collaborating teacher would like to use, I suppose.

I teach Language Arts (which is my strong point), Math, Science and Social Studies. I'm open to suggestions about what we collaborate on.