Hi Raerae:
Hardy is one of the captains discussed in 'Three Dorset Captains' which is available in paperback:
http://tinyurl.com/7jmlny5 - though it's quite expensive.
If you are happy to read on line, here's the link:
http://www.archive.org/stream/threedors ... a_djvu.txtA quite well-received biography of Collingwood is Max Adams' 'Admiral Collingwood: Nelson's Own Hero' which, though I have a copy, I haven't got round to reading yet so can't recommend personally.
if you want short biographies on Nelson's captains, try Ludovic Kennedy's 'Nelson and his Captains' (published by Collins, 1951)
An even older book is John Knox Laughton's 'Nelson and his Companions in Arms' - published in 1898, so rather dated, but quite engaging.
Your local library might be able to get a copies of these books; or try
www.abebooks.co.uk for second hand copies of this and most other books on Nelson.
I'm sure other members will have more recommendations.