I think Richmal Crompton is the name you are after.
Some of my early favourites were:
Rupert annuals
Winnie The Pooh & The House at Pooh Corner, A.A. Milne
Secret Seven series & Mr Twiddle books, E. Blyton
Just William series, Richmal Crompton
Worzel Gummidge books, Barbara Euphan Todd
The Adventures of Paddington, Michael Bond
Swiss Family Robinson, J.R. Weiss
The Otterbury Incident, C. Day Lewis with wonderful sketches by Edward Ardizzone
Later on I enjoyed:
The Viking Trilogy, Henry Treece
The Marsh King & The Namesake by C. Walter Hodges
Coot Club, Arthur Ransome
Watership Down, R. Adams