I never thought traditional English songs worked well on classical guitar ... then I heard the awesome album from 1961 with Wilfred Brown singing to John Williams' guitar. Both the singing and guitar work are truly inspiring. The album is called 'Folk-Songs' (predictably) and Belart, a division of Decca, reissued it in 1998 on CD. Tunesmith, I think that's a good a place to start as any for ideas.