The Highland Broadsword is my favorite weapon and the one I spend the most time with so I'll chime in for a minute.

There is some debate regarding the transition of a more native Scottish Highland method of use versus a later more English influenced method. I'll see if I can keep this short...
Like most swords, baskethilts went through an evolution. From the more early models in the late 1500's and early 1600's then on up through their final evolution in the mid to late 1700's and the decline in the early 1800's. For the early baskethilts, you could look to the works of George Silver for a good model to work from. I found these books to be of decent quality on Silver:
http://www.amazon.com/Master-Of-Defence ... of+defence
http://www.amazon.com/English-Martial-A ... rtial+arts
http://www.amazon.com/English-Swordsman ... rdsmanship
the third one, I feel has some flaws, but that's par for the course.
For more Scottish Highland use, you want to look at the works of Donald McBane, Sir William Hope, G. Sinclair's Anti-Pugilism, Archibald MacGregor, Henry Angelo, John Taylor, Thomas Matthewson. Now you'll need to pay attention, as these writers will frequently switch between broadsword and smallsword or spadroon. Also during the mid to late 1700's we start to see a more English style or regimental broadsword where the actions were smaller and made more from the wrist and elbow than from the shoulder. This is probably done to defend against the lighter and faster smallswords and spadroons of the time as well as reflect the regimental system of military saber that was becoming more popular.
If you look at images of Highland broadsword use prior to the Scottish defeat in 1746 you'll see a much more medieval style of use. Look at the images known as the Penicuik Drawings and you'll see they look much more like the aforementioned messer manuals than the mid 18th century regimental broadsword texts.
http://www.google.com/search?q=penicuik ... 29&bih=693
There are those who disagree with this idea and it's worth listening to their suggestions. Other books to look at:
http://www.amazon.com/Highland-Swordsma ... rdsmanship
http://www.amazon.com/Highland-Broadswo ... rdsmanship
http://www.amazon.com/Highland-Broadswo ... pd_sim_b_1
http://www.amazon.com/Highland-Martial- ... gy_b_img_z
hope this helps!
"Why is there a picture of a man with a sword in his head on your desk?" -friends inquiry