Advice on Learning “How to Think Functional”?

Question

As a newbie in functional languages (I started touching Erlang a couple of weeks ago -- the first functional language I could get my hands on).

I started to writing some

Answer 1

I found myself often getting lost in decisions such as "should I use a helper List for intermediate result storage?" and "should I create a helper function to do this?"

My advice for this: read The Little Schemer. You can follow it in Erlang. It's a good book to drill a sense of this into you.