I've just returned from 7 weeks in England, Wales and Jersey (Channel Islands). A few things came up that I thought might be helpful for others to know:
Due to budget cuts, there may be limited printed information available from local tourist offices, and you may be asked to pay about £1 for a local map or a brochure that includes a small map.
Many tourist offices have been closed, including those in towns and cities of considerable tourist interest like Brighton and Weymouth. Check online before departure. If you don't find an address, that's a warning sign.
Some towns (including Brighton) have marked "tourist information points". Those are unstaffed spots with a rack of brochures for local sights. Normally there will be a free map among them.
In some towns there is an informal location that hands out maps and might have someone willing to answer a few questions when not otherwise busy. That's at the Pavilion in Weymouth, a book shop in Mevagissey, and in the local museum (I think in Arundel). A museum is a good place to check. You can waste a lot of time wandering around, tracking down locations where--it will turn out--the tourist office used to be but no longer is.
A smart/helpful entrepreneur has put small map-vending boxes in and just outside some train stations. The cost is £1, and I think they only take an old-style £1 coin. I believe I noticed the vending boxes in East Anglia and down around Brighton, but they may be more widespread than that. The train ticket-agents will probably know where the box is located, if there is one. One agent swapped me an old pound coin for my unusable new one.
There's a relatively new Premier Inn at Heathrow's Terminal 4. (Note that I did not write "in".) I'm sure the situation will not continue once its existence is better known, but I got a room that would sleep three people for £45. I made the booking some weeks in advance, but I noticed that the rate was still under £60 the day before my arrival. The hotel, unlike the Yotel (which was up to about £100 by the time I made my reservation), is not in the terminal. It's located in the same direction as the Hilton, and you should follow signs for the Hilton until "Premier Inn" begins to show on the signage. You end up taking a skywalk across some sort of road. The skywalk is nominally enclosed but not totally sealed against the weather, so it could be quite chilly in the winter. It's perhaps a 15-minute walk from the T4 tube station and maybe 10 minutes from T4. If you are departing from a different terminal, the lifts for the shuttle trains are just on your left after you walk back into T4 from the hotel. There's a 24-hour food operation at the hotel; it may have been Pret a Manger. I was very happy with the hotel.
There are "suggested donation" boxes at the free museums and at some museums with entry fees. Don't be in a rush to make your donation. You may encounter a costly special exhibition you want to see, in which case I wouldn't feel the need to make an additional voluntary donation. Or you may find that the museum (Imperial War Museum in this case), has no separate map for sale, the only source of information being the £4 guide book which "counts as a donation". I was annoyed, because I had already made my £5 donation.
One can exit the tube at Waterloo Station without going through a ticket gate and tapping out with an Oyster Card. That incurs a penalty fare (around £7, I think) that isn't covered by the daily Oyster cap. A kind Underground employee reversed that charge for me and walked me over to the small scanners I had overlooked. They were positioned to the side and were easy to miss. I don't know whether there are other stations with similar layouts.