If you already have plane tickets, and are leaving in 1 month... I'd say you're basically good to go! I would go ahead & book yourself 3 hotels at 4 nights each, everything else you can plan after you arrive... read a guidebook on the flight over, visit the tourist office, get free map from hotel lobby, etc.

I just wanted to thank everyone for their help. We are headed to Barcelona and staying at the Astoria Hotel; to Sevilla and staying at the Casa del Maestro and to Madrid and the Hotel Lope de Vega. We are going to fly from Barcelona to Sevilla and take the AVE train from Sevilla to Madrid. I can't wait to leave on Sept 29th. I will let everyone know how it was, thanks for giving me the courage to know I didn't need a travel agent. --gem.

One good experience with a travel agent:I arrived at my hotel in Seville, after driving from madrid and was told by the desk clerk they had no record of my reservation, and had no rooms available. "If you drive toward the center of town, you might find something." I convinced them to telephone my travel agent in the states, who gave them the proper codes, and sure enough, after they were typed into the computer, the room popped up!
They do make mistakes though. It seems my rental car company in Madrid uses another name in Spain. It took several hours of trudging around car agencies in Madrid to find the correct place.