A lot of groups use PayPal to sell items, tickets, memberships and more because it is a super easy way to get and manage money. It's also really easy to add a PayPal "Buy Now" button to your site for just about anything.
PayPal offers a very straightforward Button Creator that asks you a few simple things like which email address to send money to, how much to charge, etc. If you need help on any of it, check out their very detailed guide to using the Button Creator.
For more advanced implementations, check out the more advanced guides or the developer documentation offered by PayPal.
After you've filled out the form from PayPal, you'll see a block of code they generate for you. Just highlight and copy that code then had back over to your Alumni Spaces dashboard.
Paste the HTML code into the area you want your PayPal button to show up. You have a few options for where to include the button on your site:
Any Activity, Page or News Update on your site. Just make sure you paste the PayPal code into the "Text" tab of the Content Editor. This is a great way to easy sell tickets to a specific event or collect funds on a scholarship page.
Widgets - each theme comes with a few different places where you can customize what type of content appears. By putting your PayPal code into a Text widget, you can feature the button on nearly every page for most themes.
Your Group Description in the Site Settings - this is a good option for membership sales and other things you want to appear on most pages.
That's it. Now sit back and watch your money start flowing in!