We've been to Barcelona quite a few times now - mostly for testing but once for the race.
It isn't the easiest circuit for overtaking, so don't expect much. On balance my own preference for location is right at the end of the straight before turn one. I do appreciate an F1 car accelerating and cornering, but there's also something very special about seeing one decelerate from 300 to 70 kph in the blink of an eye. Especially now in the V6 turbo era, there are so many different noises you can hear - it is an orchestra of power. From F you can see the pit exit, turns 1 and 2, entrance to turn 3 and turn 7.
We've stayed in a few places, from further out so that we could get an easy train to the circuit to right in on roads just off Las Ramblas. If there are a few of you and you can't be bothered with the train then a taxi is €50 - €60 from the centre to your chosen circuit gate. Fairly common now I think, but Circuit de Catalunya won't allow you to take glass bottles in, and if you've lots of plastic bottles of booze then expect them to also remove the tops if they're feeling strict.
Food is what you'd expect - burgers, chips, fried potatoes and cheese stuff, sausage.
We're actually a bit bored of Barcelona now, so we're staying in another town this year for testing - Sabadell. Closer to the circuit (we're driving this year) and just fancied a change of scenery.
If you're there on Thursday then go and queue at the track entrance behind grandstand J (the one before the main one). If you get there an hour before they open the gates (think it is 1 pm) then you'll be able to dash through and get a really good spot in front of your chosen garage. Needless to say, they're all Alonso and Ferrari mad so if you support another team you should be able to get right to the front if you get a jog on. Great opportunity to chat to the drivers and get a few things signed.