From time to time, people wander into the Forum and revive very old threads more-or-less at random and for no obvious reason. This is one such. It was nearly 11 years since it had last seen the light of day when somebody calling themself 'GUEST,ceza' remarked 'ghh' a few short hours ago.

I thought I'd better mention that; sometimes people don't notice the date and pick up the conversation as if it were current, which can confuse others later on.

Occasionally, though, this sort of random grave-robbing can give us the opportunity of updating old information, correcting misinformation or even adding something new. Jim and John have done a bit (though be honest, you two: did you both see the date on the original question?) and I'll add some too, starting with earlier comments.

• The English Folk Dance and Song Society was formed by the amalgamation in 1932 of the Folk-Song Society (est. 1898) and the English Folk Dance Society (est 1911: Sharp was one of its founders). Describing Cecil Sharp House, its headquarters in London, as 'an English folk club' is a bit like calling the Empire State Building 'an American office-block'. EFDSS hasn't been at that 'webfeet' address for many years now. The 'new' website is at  http://www.efdss.org/.
  
  It's actually a set of complementary sites. See also, in no particular order:
  
  http://library.efdss.org/  The Vaughan Williams Memorial Library. Among other things, the site has full indexes of a number of important manuscript song collections, including Sharp's; the Roud Folk Song and Broadside Indexes (the folk song index is the most important finding-aid for traditional song in the English language ever developed, and continues to grow) and a good selection of photographs that Sharp took of singers he met in both England and America.
  
  http://eds.efdss.org/  English Dance and Song: the EFDSS magazine. Includes features audio files augmenting the print edition. Relatively new, so it doesn't go back a very long way yet (ED&S has been running since 1936; its immediate predecessor, EFDS News, ran from 1921-1936) but archive material is gradually being added.
  
  http://fmj.efdss.org/  The Folk Music Journal. The scholarly side of the Society's work. Includes contents lists for 1874 to the present date. FMJ is the successor to The Journal of the English Folk Dance and Song Society (1932-1964), The Journal of the Folk-Song Society (1899-1931) and The Journal of the English Folk Dance Society (1914-15 and 1927-1931).
  
  http://folkopedia.efdss.org/  A wiki devoted to traditional music, but unusual among wikis in that it's peer reviewed and all contributors are expected to use their real names. In its early stages as yet, this will eventually grow into a considerable resource available to all.
• The Dover facsimile reprint of Sharp's One Hundred English Folk Songs is probably still available from the publisher. Jim is right to think that the Karpeles Cecil Sharp's Collection of English Folk Songs is long out of print. It can still be found, but you can expect to pay a serious price for it. It isn't the entire collection (which is very large) and it had its faults, but it's still very extensive and very much worth tracking down if you're serious about the subject.
• Lamarca's comment (made back in 1997) didn't refer to Dear Companion, which wasn't published until 2004, but to 80 English Folk Songs From the Southern Appalachians (London: Faber & Faber, 1968 and subsequent reprints). Not mentioned as yet is Still Growing (London: EFDSS, 2003), a selection of songs from Sharp's English collections which places the emphasis on context, featuring photos and biographical details of the singers concerned. John has already provided a link to EFDSS' online shop.

Sharp died in 1924, so much of his work is now out of copyright. Some of it has been appearing recently at The Internet Archive. At the time of writing, there are books about morris and sword dance and country dance, together with song resources such as One Hundred English Folk Songs; English Folk Songs from the Southern Appalachians (the original 1917 edition, co-edited with Olive Dame Campbell; the later and much larger edition was edited by Maud Karpeles after Sharp's death and is still in copyright); the influential but nowadays very old-fashioned English Folk-Songs for Schools (a collaboration with the Rev Sabine Baring-Gould), and English Folk Song, Some Conclusions: this last being Sharp's study of the subject based on his work collecting in Somerset. Written in a hurry and very early in his collecting career, it was a preliminary study only and wasn't intended to be definitive even in 1907. A follow-up written from his later experience would have been rather different and today it is very dated indeed, but still essential reading provided people take it in the context of its day and in the light of subsequent scholarship.

C J Sharp at the Internet Archive  -available in facsimile: pdf and other formats.

Google Books has some material too, but such as there is is mostly witheld from users outside the USA. There are plenty of other Sharp song resources scattered about the web these days, of course, some good and some less so; but this lot should be enough to be going on with.