Bill Nicholls completed his primary education at Macarthur Street State School, Ballarat. He taught himself drawing and painting; and in middle age acquired enough Latin to draw up his own diagnosis of the many new orchids that he published.

Publications
1925-1950 about 100 papers for the Victorian Naturalist; published his first paper titled 'Propogation of our Pterostyles' in December 1925. In the decade before 1950, Nicholls wrote forty-one papers for the Victorian Naturalist.
34 page article in the Sun Nature Book No. 5 (Gems of the Bush, 1934) 'in which 80 line drawings, 70 photographs and four plates in full colour amplify the descritive text on many Australian Orchidaceae'.
Articles, drawings and water colour portrayals also appear frequently in other journals, and in the newspapers descriping trips and expeditions.
Nicholls worked for 28 years accumulating material for a monograph that would adequately describe and figure in colour every orchid indigenous to the Commonwealth, excluding Papua - about 600 species. The monumental work, to be published in parts over a period of years, was in the printing press when Nicholls died.

Expeditions
Otway Ranges and eastern highlands - Baw Baw, Mount Wellington, Howitt, Cobbler, and the Barry Mountains.
1946-1948 Visits to Western Australia in the Spring of 1946 and 1948 under a grant from the Maud Gibson Trust (Royal Botanic Gardens Melbourne) to make drawings on the spot and collections of endemic and very localised orchids to fill up the gaps in his Gallery of Western species.