If there's already a comprehensive thread around - please give a link to it.
So far i'm only sure about three things:
1) と is used to explain a natural course of events like 四月になると雪が溶ける
2) なら is used to make a suggestion like ロシア料理なら、オクローシカがいいでしょう
3) のなら is used in "if that's the case" constructions like 本を返しに行くのなら僕のも返してください
While i use ば for general conditional structures i wonder if たら was more appropriate is some cases. That being said - i don't get the difference between the two.