I'm a massive fan of using a peice of online software called CloudBeds.
I'm 100% unaffiliated with them, But 100% a fan.
It allows you to:
1. Automatically take bookings from Hostelworld, Booking.com, Agoda Etc Etc. More OTA's are being added all the time.
2. Instead of alocating X% of your rooms per service, It lets you put ALL your beds onto each booking engine, And once a room is booked it automatically lowers the avaliability on each platform. This leads to more beds filled and less overbookings.
3. Great Statistics! See that you've got a mid week slump in bookings? Shit, Time to throw up a 25% off promotion across all platforms *Which you can do through the Cloudbeds app* and get the beds filled!
It does cost a monthly fee, Which depends on the number of beds avaliable.
They've also got the best customer service across any booking management system I've ever experienced.
Throw them an email, Explain that you're a volunteer and want to show the features to your boss and they'll hook you up with a demonstration account.