So you've decided that you want to become a mentor, congrats and thank you! Now it's time to find someone to mentor. Sure, these people are all over the place, but tracking them down can prove quite difficult. Let's talk about a few places that I have had luck finding developers to mentor.
Universities, Colleges or Technical Schools
Most program leads or professors would be more than willing to recommend a few students to reach out to. They know how important it is for students to learn skills outside of class.
Public High Schools
I never would have thought that high schools would be a good place to find new developers. Most high school students don't usually know what they want to do, however, there are quite a few students that are introduced to coding in high school and have a passion for it. You may be the person that encourages then to become a developer someday.
Other public or private schools with soon-to-graduate students
There are other schools besides public high schools, such as Religion-based schools, charter schools and other private schools. These places often encourage third-party or custom extra-curricular activities. I created an Intro to HTML & CSS offering and taught at a charter school with 10th to 12th graders last year. When approaching schools, start with the guidance counselor or activities director, there may be programs or offerings you can contribute to.
Code Schools or Coding Bootcamps
This is probably the best way to find mentees, at least for me anyways. My local code school, Prime Academy, does a call for mentors with every cohort they do. You can choose to opt in (or out) with each new cohort. Code School or Bootcamp programs are shorter and the students are very enthusiastic - most times they chose this shorter program offering because they want to become developers (yesterday) and have a major drive for success and enthusiasm that is contagious.
Local Organizations or Meetup Groups
Another really great way to find mentees is through local meetups, tech interest groups or local organizations. I actually got started in mentoring by teaching classes with Girl Develop It. Many nationwide organizations have local chapters that you can get involved with - if not, create your own! Other notable organizations I would recommend are Yes We Code and Women Who Code.
This is probably the funnest way to meet mentees! There are a lot of awesome hackathons out there, including nationwide and local initiatives. I participated in a local event called Overnight Website Challenge this past year and I met a lot of really awesome people. Our team was comprised of a couple new developers and they were vital parts of our team and contributed greatly. You can usually either create a team or volunteer. They are always looking for volunteers for these types of events.
Conferences or other tech events
This one is a little more difficult, unless the event has a special table or area for this sort of thing. However, if you are an extroverted person you could easily attend a conference and network your way to a few possible mentees.
Each local area is completely different, I am lucky to live in a tech saturated city (I <3 Minneapolis) and have a great deal of opportunities to find mentees and opportunities to contribute.