Giving back to my undergrad program So, I'm starting up a small business (a software shop) and as far as I'm concerned, that puts me in the 'giving back' phase in my life. One thing that I'd like to do is help my alma mater improve its CS program. Now, I don't have much money (see: starting a business), but they don't  really need stuff, they need curricular assistance. 

The program is great, as long as you're trying to move to a grad program. If you're trying to turn 'knowing things' into money, it's...less good. Not much in the way of an internship program (no internship program), source control only recently introduced, no experience turning requirements into software, etcetera. Like I said, it's a problem. 

I want to actively participate, if they'll have me, including offering internships (paid internships!) and guest lecture about working in enterprise-level software development environments.

My question is this: how do I make contact with my former professors and bring about the topic of altering the curriculum and/or helping out?
I was in a similar position a few years ago, only it was test equipment that I was trying to help them acquire. I managed to help them get a $500k piece of test equipment for free, but it required a lot of negotiations and navigation of department politics. You just have to reach out to the professors and develop a dialog with them if you haven't already. 

I suggest you take it one step at a time and don't expect sudden, radical changes. Perhaps you contact a professor, tell them about your company and let them know you'd like to hire some students to work part time. Whether you call it a co-op, and internship or ,whatever I'd think most departments would be eager to present such opportunities to their students. If you don't get a good response from the professors you can always take it to the department or the school employment office. 

As to guest lecturing, rather than expecting to come into a class, you could reach out to some of the department's student groups about coming to speak as a way to test the waters. You can always offer to come as a guest lecturer to a class, but devoting a class session to a guest (unless the class already has plans for guest lecturers) means that much material that the class won't get to cover. 

Your success will largely depend on your attitude in approaching the people in control, how they remember you and how you present your ideas. You won't have much success if you charge in telling them that their program is "only good if you want to go to grad school, but crap for going out into industry" even if that's true. If you come back and start an honest dialog about wanting to help and sharing your ideas on how you'd like to help, that's more likely to be successful.