Not the reaction I expected, but a valid one!
Here goes:
There are best practices on the organizational side. I'd have to do some research to determine nonprofit and civic organizational adoption. My gut is that at least in the US, best practices adoption for volunteer engagement/management is not widespread. In my own experience, very few of the organizations I've worked with or know even kinda well have the capacity (and/or interest) in implementing best practices. And I would assume that informal neighborhood groups are not adopting them.
From the perspective of an individual, there are resources for identifying volunteer opportunities, though this various by jurisdiction. Some places have active and robust volunteer referral systems while others have lots of active civic groups (think Jaycees, Junior League) that are central to life in that place. Other places have nonprofits and people volunteer there.
What resources could help? Good question. I think that depends on what 1) people want and 2) organizations want.
In my experience, many people who volunteer approach their voluntarism as "take what I give you." Meaning, "I will give what I give, when I decide to give it, how I decide to give it and I'll do it the way I see fit." In some cases, this might work for an organization. I've seen it be accepted by organizations because the organization does not have time (more likely has not made time) to develop a volunteer program with job descriptions, intake, and every other important element needed. If an organization were to develop a volunteer program, a bunch of resources are needed including staff.
Back to my original comments for a sec. Getting involved is kind of like the wild wild west. Jump in an do something, there's little organization or governance, particularly on the street-level stuff of trash pick-up, etc.
Here's an example: When I worked for then-Mayor Vince Gray, there was one winter that was colder than usual. VCG wanted more than the helping the homeless during hypothermia season status quo. So leadership and staff got together to develop the city's cold emergency plan. Basically, anyone without shelter was encouraged to get on a bus or go into a non-shelter on the coldest nights. We fed people, gave them stuff (dry clothing, etc.) and caseworkers were available to help if people wanted.
At something like 2a on one of the first days of this plan, I was doing a site visit to a bus. (Did the staff need food, water, etc.) It was dark out, save for the bright street lights that made the snow-covered everything sparkle. All of a sudden, there's singing and laughter. A small group of 20-somethings came in happy as could be carrying cups of hot chocolate, boxes of donuts, hot pretzels, and more. They handed the food out, chatted for a few, and then took off for the next bus. This merry band of do-gooders made me smile. They made many on the bus smile. They came out in the wicked cold to make sure that people who were homeless had warm food and drink. All I know about them is that they lived around Georgetown and were in professional programs.
Stepping up, doing something can be something as simple as this.