Microfilm copies of Lebanon Census exist for all years from 1790 to 1930, except 1820. The 1820 records for all of Grafton County are lost. Microfilms are available at the National Archives Repository in Waltham, Mass.
The Jones Media Center in Baker-Berry Library at Dartmouth College has microfilm for most of the 19th century census of Lebanon and the rest of Grafton County.
The Lebanon Public Library has microfilm of the census for the state of NH for the years 1910, 1920, and 1930.
Ancestry.com has scans of the entire extant census records online for a subscription fee. These images are much better than the microfilm versions of the same records. The Lebanon Library has a subscription to AncestryLibrary that can be accessed at both the Lebanon and Kilton Libraries.