How many times have you heard bad training advice?  Right; there's a lot of it.  Here's a quick list, plus some (hopefully) good advice as well.

More is Better.  
Maybe not - without rest and recovery, the stress of training just makes you tired instead of creating an adaptive response.

Just Run.
Most other sports emphasises technique, while some runners just run a lot - cardiovascular training is imperative, but poor form can lead to injuries and is inefficient.