Hi Vikb -
Fundraiser here - U.S.-based. If I were looking at potentially giving money to ANY charity, here are the steps I would take:
1. Research, research, research. I don't know the rules for Canadian charities, but U.S. non-profits are required to make public their tax returns. Not always easy to find, but they're out there.
2. Volunteer. Since you already do this, you can always ask someone at the charity how many people give, what they give, how gifts are managed, etc........
3. Listen to the charity's messages. They'll tell you what their priorities are, what they'd like you to fund, but, ultimately, it's up to you - it's your money, so you can tell the charity how you'd like your gift used, be it scholarship, money for lab supplies, hell, money can be designated for landscaping.......
4. talk to a lawyer/charity advisor (yes, they're out there) about what you'd like to do, and how you'd like to give the funds.
5. When you're ready, contact the charity, and tell them - I'd like to make a gift. What are your short and long-term needs? what are your goals? How's the payout rate on your endowment? What's the size of the endowment (insert Butthead-like laugh here)? Can you send me information?
Making this sort of gift is a long-term process, and, ideally, the charity will want to build a relationship with you. You can always start with a small gift, see if the charity thanks you, updates you, asks for more, etc. before making any more decisions.
If you're interested in giving for scholarships, you can give annually, then think about a lump-sum after you see how the school manages your gift.
Good luck - and thank you for giving to charity. There are lots of good ones out there.