Having decided the area of the project, the next thing to do is to obtain the relevant maps.
Although the 1:50,000 Ordnance Survey maps are useful for a general overview, they are totally inadequate for detailed field work.
The 1:25,000 maps are by far the best. They not only show accessible roads for cars, footpaths and all field boundaries, but the contour interval is normally sufficient to indicate the natural topography of the area. In addition the scale is large enough to allow generalised plotting of sites and even rough plans of earthworks.
The 1:25,000 maps are expensive, and an area will often spread across two or more maps. EMAS can offer A4 PDF files of 1:50,000 and 1:25,000 maps of the whole of England. Moreover, one can print off numerous copies of the maps and annotate them in the field.