Hi,
The Best reference you will find on the Lonsword/Bastardsword/Hand and a half sword is Christian Tobler's "Secrets of Medieval German Swordsmanship" available through Chivalry Bookshelf.
There has never been anything on the market like this book. Christian has meticulously examined Lichtenauers' verse as well as Sigmund Ringeck's commentary and written a step by step manual that (with some experimentation and practice) is quite capable of being a stand alone resource for Longsword practice. This book also contains information on armoured combat with spears and swords as well as a small section on sword and buckler, on wrestling and on mounted combat.
I would also recommend "Medieval Combat" by Mark Rector available through Greenhill books. Mark has translated Talhoffer's fechbuch of 1467 which is a great resource for the slightly more advanced swordsman as well as those who want to branch out into other weapons. It contains sections of Longsword, Messer, Poleaxe, Sword and Buckler, shield use, dagger and wrestling. (Don't think I left anything out).
Both of these chaps (and others) can even answer questions for you on Swordforum. How about that!!
I cannot second the recommendation for Mr Clements books. He is a wonderful martial artist who has done alot for the WMA community but I think he would be the first to admit that the information in his books is out of date in comparison to the knowledge the he and the community as a whole has today.
Cheers
Stu.