Well... "I have not been there", I happen to have been born there and live there, so I can't help you with hotels, sorry :) but once you've zeroed on one I can provide info on location and convenience if you like.
Barcelona is a large city (as in population) albeit quite compact in size, still, there are lots of things to do/see. I would strongly suggest having a look at these websites so as to make a list of wanna-do stuff and then perhaps more concrete advise can be provided:
http://www.barcelonaturisme.com/wv3/en/
http://www.infocatalonia.eu/
http://www.timeout.com/barcelona
http://lameva.barcelona.cat/en
http://www.barcelonaesmoltmes.cat/en/inici
http://patrimoni.gencat.cat/en/discover/search
Once you have a rough itinerary, it's far easier to advise and provide tips.
And let's not forget heritage and tradition
http://lameva.barcelona.cat/culturapopular/en
and finally, in case you still think you might get bored, take the pulse to the city:
http://guia.barcelona.cat/en
If anything, a few initial pointers for you:
1.) In August is hot, really hot (and sometimes humid, and that's what kills you!), and for a Canuck that'll be a bit of a shock if you haven't been before in Mediterranean cities in summer. Just be prepared.
2.) While we receive visitors (business, tourist, schoolchildren, retirees, concerts, congresses, sports events...) all year long -18 millions of you each year- Jun to Sep are the months where this is especially 'problematic' so expect lots of people everywhere. Do pre-book everything you can... if the website of the attraction you want allows online pre-booking... do it, if not, well, expect to queue. That's the way it is, sorry, don't complain, we residents 'suffer' it every year, LOL!
3.) So you don't speak Spanish... so what? it's not the local language anyway. Spanish is co-official here in Catalonia but the local language is Catalan. Regardless, for one thing, we have lots of expats and migrants from all over the world living here so lots of other languages are spoken as well, including English; and also, theoretically most of the under 50 born-locally residents should speak (or at least mumble) English anyway as this, alongside French in some cases, is studied at school.
4.) Directions to/from.... once you've chosen your accommodation that'll be far easier... right? :)
Enjoy!
