Welcome to London!
Books for Cooks I understand is still going strong, though I've not been there in a while
https://www.booksforcooks.com/
It would help if you could give us some idea of neighbourhoods, or cuisines you are interested in, London is just too big to list a few "best" places
Some of my favourites haven't survived the pandemic
i often head for the Covent Garden area, where you find Lahpet West End (Burmese) and Darjeeling Express (Indian) and a couple of Indian places that are small chains available round London, Dishoom and Masala Zone (have a thali tray and the Covent Garden branch is the best)
For more traditional but with a twist I'm a fan of Adam Handling,but haven't been to his current location, Frog, also in Covent Garden
If you want to get away from Covent Garden the Coal Yard at Kings Crossis the boom place for eating, lots of individual restaurants, and south of the river I like Chez Bruce and Trinity in Clapham, both institutions of fairly classic cooking, and in Soho Quo Vadis, and nearer the City St John Bread and Wine
Eater London is a great guide that's up to date
https://london.eater.com/