Some sources to encourage further research:

For research based on DNA, under the "Clan MacLeod Surname Project"

Family Tree DNA MacLeod

For research based on DNA, under the "The MacLeod Septs Project"

Family Tree DNA Testing

The ACMS web site lists a Genealogy Committee 

The Associated Clan MacLeod Societies Genealogy

The Clan MacLeod USA site also has some good resources

Clan MacLeod USA Genealogy

The Clan MacLeod Societies of Canada (CMSC) has collected a lot of information, which is housed at the University of Guelph. 

There are many genealogy sites on the web.  A few of the better ones are:

The more information that you have the better: town of origin, name of ship, points of departure and arrival, alternative spellings of names i.e. such as the interchange of McLeod and MacLeod, occupations, known relatives, etc.

For anyone with Cape Breton, Nova Scotia roots, there is a huge website 

Morrison/Ross/MacLeod Settlers in St. Ann's Cape Breton

managed by Russell Johnson, that has over 103,000 names in it.

The MacCrimmons are hereditary pipers to the MacLeod and it is fitting that we also include a link to the work being done on Family Tree DNA clan projects using DNA from people of various MacLeod and MacCrummen/MacCrimmon family tree branches.  The goal is to study and analyze DNA results including YDNA, mtDNA, and autosomal DNA for males and females.  While these projects are located at Family Tree DNA (FTDNA), men and women who have tested at Ancestry DNA can copy these results to our projects at FTDNA, thus adding more people so we can better understand our genetic roots. Here is the link:

​MacCrummen/MacCrimmon family tree

Folklore and History
There is some material on the ACMS website and in the Clan MacLeod Magazine.
For a rather academic look at our history, see: J. F. Grant, "The MacLeods: The History of a Clan", Faber and Faber Ltd, 1959 reprinted, Spurbooks,1981, 642 pages.

The MacLeods of Glengarry 1793-1993" (Revised Edition) prepared by The Historical Committee of The Clan MacLeod Society of Glengarry 1993 - ISBN 0-9697345 has very important geneological information of MacLeod families settling  in the Glengarry area of Ontario.

For a different perspective, looking at how MacLeod's fared around the world, see:
James Hunter, "Scottish Exodus: Travels Among a Worldwide Clan", Mainstream Publishing, Edinburgh, 2005, 414 pages. That book, and a number of other MacLeod publications are described, and can be ordered from the web site:

ACMS Books

For a couple of histories on MacLeods:

Clan MacLeod history and You Tube videos
Clan family histories MacLeod

Overview of Scottish clan information

Scottish Clans and Tartans FAQ

Hopefully, all of this helps with an understanding of the Clan MacLeod is all about.