Am planning to go London in Sep/Oct. Notice that Sep hotel charge is much higher. Why is it so ? And also, any recommendation of good and affordable hotel that near place of interest.

Having worked and lived in London for 7years, September is treated as peak months, best thing you want to do when looking for accomodation, is try and be close to a railway station (fares are reasonable), depends how far out you go but try and do it so you can be inside central london 30 mins then the cost drops accordingly further out you are, but being in the railway industry trains run through til after midnight frequently.

If you're looking for somewhere to eat out - try www.hot-dinners.com - it's a good site for bringing together reviews of all the really good restaurants as well as featuring news on what's going on in the London restaurant scene.