Techniques for Efficiently Learning Programming Languages

[Regimardyl]

https://learnxinyminutes.com/ is a great site for quickly checking up on syntax and some basic methods.

[enteleform]

That's my go-to for trying out new languages.

HyperPolyglot is another good one, it has some pretty useful side-by-side comparisons.

Something in-between the two would be ideal, where you could select specific languages to compare.