Advice from a relative newbie: No triangles! Can you tell that those are my bugaboo? Rail fence is a great pattern and makes an amazing design. Looks like warm wishes would be wonderful also. And, just today, I saw a thread about the design called 'potato chip' or 'rainy day'. They seem to be made up in just two fabrics, but you can use three -- there are no quilt police here.
But if I were you, I'd maybe start smaller than a large bed quilt. Try a lap quilt first, and then move up!