When I'm in Oxford I often go there for lunch - they do a decent pub lunch. The Eagle & The Child is on the west side of the Woodstock Road just as the Banbury Road is forking off of hit, about 1/2 mile north of the city center. They have a lovely display of photos of the Inklings but they'd done some remodeling the last time I was there...
An English pub is quite different from an American bar - I don't think we have anything equivalent. It's a "public house" - they often serve very good food (but, as above, re: Bird & Baby, lunch is served in a narrow window of "lunch" hours - you can't get "lunch" at 4 p.m. and I don't think they do dinner...) and they serve as a community meeting place. I'm sure some folks get drunk there but I've never seen it. The British do drink more than the Americans, just in general, but there are nice things you can drink which are non-alcoholic. Or you might try cider, which is slightly alcoholic (if you can call 7º 'slightly alcoholic' - Ed.) and you can get it sweet or dry (personally, I prefer the dry) - you can get a rather interesting drink called "shandy" which is half beer (lager or ale) and half lemonade - but don't worry! Their "lemonade" is what we call Seven-up!!! (an Englishman would argue about that - Ed) It's rather nice.
Some pubs are better/nicer than others, some are downright posh. But the Eagle and Child is rather homey in a very pleasant way, not dank at all. There are two front rooms (you enter through a hallway between them) one has a fireplace, then the ordering area (you go up to the "bar" and give your order; look around for the chalkboard with the food specials on it), then it continues to the back and they've added some rooms to it, so it's larger than it used to be.