First bike

Hi all I'm looking for my first road bike, I've ridden a kmart bike regularly for the past few years but I'm hoping to get more serious about cycling I don't have a lot of budget so I'm looking 2nd hand with some budget left over for a service. I found this at a 2nd hand store, could any one give me advice?
Is this a good deal? If not, what should I be looking for?

I have been to a bike shop and have been sized up on a giant brand bike, are sizes the same between brands?