You might have a good core already from that - I just know I hadn't been riding in a long time, got a road bike and I can definitely tell that my riding position and such has changed over the last year. I'm completely happy with my bikes this year - whereas, last year I was periodically miserable.

We can all give you tons of wrist positioning advice when you get your new bike!

The ruby's are nice bikes with comfortable positioning.

You're about 5' with a 28.35 or so inch inseam - so I don't think you really have a body that requires a WSD - You don't have long legs for your height. I'm 5'1 with a 28-29 inch inseam, and I don't like WSD bikes. The top tubes are too short for me.

I test rode a 52" specialized ruby comp once in the fall and I was fine on it, inseam & top tube length... It was set up very similar to my 49 cm marin bike (I'd brought my bike into the shop and they measured everything to set up the comp like my marin) - so I would think the 48" would probably work for you - but test ride and see what feels fine for you.