I recommend this one. It was made specifically for players with high level characters.
http://wow.thenoobschool.com/power-level-mining-guide-1-375
Under each section of the guide(as in ore type, mithril, thorium, so on) there is an extended guide to mining for that specific ore. The links are hard to find as they are differently colored, but aren't that easy to see. Look for sentences like...
Quote:
More Thorium mining routes are available from the Thorium Mining Guide.
and click on the Thorium Mining Guide.
At the bottom, there is also a guide to powerleveling mining through smithing.
The only additional help I can provide is that this mining guide for Silithus is bad, as he never ventures into the three hives for nodes, where you can often find 2-3 nodes per hive, with plenty of rich veins.
Hope this helps!