Scandinavian Defense

This opening has caused me a few problems - how do I stop the queen doing serious damage to my kingside please?!

Move 5 hangs a pawn.  You have a ton of options to avoid this line, although honestly, if you're careful with your pieces you shouldn't even bother to since you'll be so far ahead in development.  The first option is to not take the d pawn on move 2.  D4 is a good alternative response and if he takes your epawn, it's very easy for you to get your material back later.  Another option is to not immediately chase the queen with the queen's knight.  Play the king's knight instead and you'll have a much easier time castling.  Also on move 4, you can just block with the queen.  If black takes, you're ahead on development, if black doesn't take, you can castle easily either direction.  By either playing d3/d4 or fianchettoing the white bishop.

5.Bf3

2.d4, transpose into the Blackmar-Diemer Gambit (1.d4 d5 2.e4) and screw all your opponent's preparation! That's how I now tackle the Scandinavian, and I don't feel as uncomfortable as I did when I faced it!

Conzipe's right.

Indeed. It may seem damaging that after ...Qxg2 white has his kingside split and his rook threatened while simultaneously a pawn down. However, that is to miss the big picture -- white will get his rook into play on g1 and black will not be able to cause white any harm with his underdeveloped position. The kingside is not really weak if nothing can get to it, meanwhile white is quickly building up an attacking force that actually is dangerous, because it involves more than one piece and thus potential attackers. Of course for king safety he always has the queenside. It is going to be way too hard for black to catch up in development as threats pile up if he is to hold on to his pawn.