How to mentor a junior programmer

Does anyone have any suggestions on how to mentor a junior programmer ? If you have mentored someone did you follow any process or was it quite informal ?

If you've been mentored in the past what kind of things did you find most helpful ?

Try to set aside between 30-60 minutes a day to review their code together. If you can't do this, then try to get together to review their code whenever they make a code commit, unless it was very basic. Have them explain why they chose the approach they took in lieu of others. A process like this helps to establish a great relationship, as well as really stimulate the student to think on their own and be able to defend their decisions. Not only does the student end up with someone approachable whom they can trust, but you'll notice an improvement in their quality of code and logic almost immediately.

Edit: Also, If you are unable to commit this much time to co-review with your junior, then you probably shouldn't be mentoring them and instead see if anyone else has a schedule that would allow it. The whole point of mentoring is to actively aid in the professional development of the student, and they're not going to learn much if proper attention and guidance is not given to them.

I had the chance to work as an intern (one of two) in a small software company and had the opportunity to work on an "almost new" project they had. They had me set up with everything needed and gave me an introduction into what the project actually was (basic stuff like what the requirements were etc).

At first we got to do minor tasks like researching things that mattered to the project (they had given us a list of topics). This was, I think, to see how much we could handle ourselves, as the things we needed to look up and research were not that trivial and it took a good 2 weeks or so (counting the basic demos we had to create for it). That testing phase was actually done really without much 'coaching'.

However, after that period we could work on the actual project itself. This was also the moment we began to be coached together, in a similar style to pair programming, except there were three of us (2 interns and 1 'coach').

We learned a lot from him, but it was in an informal manner, and he didn't act like the 'all-knowing-listen-to-me' guy. When we had suggestions he would listen and think through with us whether they were any good. or give his view on why an idea should not be done in that way... Now that I think of it, he actively encouraged us to make suggestions, and to think about better ways to do things, instead of just sitting there 'taking orders' from someone who probably knows what to do better then you.

So in short:

• Let the junior programmer work (mostly) on his own to study the materials at hand, give him a list of minor TODO things like looking up information, or building small demos.
• Check the work he has done regularly and advise him if there are better ways to do things. Also point out the items he actually did well, that way he'll remember those for later.
• Let him work on a real project, and mentor him by working together at the same project, giving him advice when he has questions.
• The effort has to come from both directions: encourage him to ask questions, to challenge 'the way it is currently done'. Ask him questions on how he thinks it should be done and give him your opinion as well.
• Make it 'enjoyable' - don't let it look like you are giving orders.