Have fun! I've done quite a few volunteering trips, but the ones I felt made the most difference were when I went to Uganda and taught in a primary school for a total of 5 months. It was an amazing experience and now I'm starting a course to become a qualified teacher in a few weeks.
Drink in all the information you can and try not to make jugements about what you see; just see it and learn from it. Be prepared for things that seem completely off the wall or a bit scary and unknown - go with the flow where you can (and where is safe, obviously!!). Things will rarely go to plan but that's ok.
Something that is also important to know going into something like this (or I think so anyway!) is that you can't fix everything. The first time I went on a trip like this to Tanzania when I was 16 I cried for weeks when I got home because I felt like I hadn't done enough. My trip had come to an end and I hadn't been able to help everyone who needed it, but I'd gone home anyway. It took me a long time to figure out that while the number of people I had helped was tiny compared to the rest of the world, it was a million times better than if I hadn't gone at all.
Enjoy and let us know how it goes!! xx