Scottish Clan and Family Encyclopedia (not that good, but the sale price was good)
Beerbecue,

If you're referring to Way and Squire's "Scottish Clan and Family Encyclopedia", then you've actually got a very reliable resource on your hand -- it's one of the better works out there on the subject. Both authors are affiliated with the Lyon Court and the Heraldry Society of Scotland, and "know their stuff".

Cheers,

Todd