We are heading to Barcelona for 8 days visiting my son studying abroad. That will be our "home" location, but would like to see other cities, suggestions? Is there enough to do in Barcelona for 8 days?

You could take a few day trips:
,,,Girona, Sitges, Tarragona, Montserrat..

Girona and the Costa Brava. We did a 3 night roadtrip from Barcelona; stayed one night in Cadaques, and 2 nights in Girona. i think you can see a lot in Barcelona for 5 or 6 nights.

Do you have a guidebook? In Barcelona we saw a lot of the Gaudi sites, such as Sagrada Familia, Parc Guell, Casa Battlo and Casa Mila. Had a tour of Palau de Musica, visited several churches, Montjuic, Citadel park, & enjoyed walking around the neighborhoods.

Our favorite restaurant - Cerverseria de Catalana on Mallorca St.

You have a treasure trove of options! You might want to consult the Michelin Green Guide or Rough Guide to get a good sense of them.

And you might find some ideas in my trip report:
http://www.fodors.com/community/euro...-catalunya.cfm

Unlike KarenWoo, I was disappointed with Cerverceria Catalana -- it was one of the 2 or 3 <b>least</b> enjoyable meals that I've had in Spain, and I've been fortunate to have spent nearly 8 weeks in that country. Rushed, brusk, and unhelpful service; only 1 of 4 tapas I ordered was tasty, one was inedible.

Bookmarking

CC seems to be a victim of its success
When I first had a meal there ( about 9 years ago). - it was excellent.
The last time ( in the fall of 2015) - not so much.

The Costa Brava is wonderful!

Thank you for your advice. Do you suggest guided tours of anything or on our own? Do you think Seville is a must see? What's to do there? Valencia is easier to get to, things to do there? Any comparison of the two cities?

If you wish to see a completely different part of Spain, visit Seville
for a taste of Andalusia. Vueling has cheap flights.

Valencia is lovely ;it is "closer" to Barcelona in terms of geography, language,
etc.

More than enough to do in Barcelona for 8 days, here are "100 reasons to visit Barcelona": http://www.barcelonaturisme.com/wv3/en/

Sevilla would be something completely different. The queen of the cities in the south, thousands of years of Roman, Christian, Jewish, Moslem and gitano history and culture, modernitiy and history hand in hand. Lots of historic sights, the Jewish quarter, much of the city is like a museum in itself, experience real deal flamenco, splurge in boisterous tapas bars and join the outdoor nightlife in plazas and parks long into the small hours. http://www.andalucia.com/cities/sevilla.htm

A taste of Sevilla: https://www.youtube.com/watch?v=7mFE9k0E-2Y&t=108s

A cradle of the powerful and beautiful flamenco culture: http://www.bbc.com/travel/story/2012...flamenco-scene

Highly reccommend the town of Calella (Not Calella de palafruggel)which was an hour outside of Barcelona on the coast.