Hi Greg,
many of the post cards we collect, we add to our album pages, together with the stamps and detailsof the lighthouse.
Others we have put into special ringbinders, for which you can buy insterts with "post card pockets".
But my favourite way of storing them - and I think also the cheapest - is fixed with photo-corners to a page in ordinary ring binders. The paper is a bit thicker, so it is strong enough.
That way I can get 2 cards on a page and a little bit of space to write something with them. And they are easy to sort, store and look at that way.
Have fun!