You first want to make sure you have adequate drip edge flashings, In some conditions, the average 1 by 2 or even 2 by 2 drip edge flashings are not enough.

But, after it's felted, take some of you 3-tab shingles, and cut off the tabs, leaving only the rectangular sections with the asphalt sealant strip. Take these and simply line them up and nail them down on the drip edge. Keep in mind these will set the course for the rest of the roof. You'll install 4 nails per "starter" shingle.

There ARE directions on every package of shingles, and you can go to any of the manufacturer's websites and locate PDF formatted installation instruction, including all the details, such as valleys, pipes, chimneys, etc.

A roof CAN be your friend

Tried to post my second reply yesterday.....hmmmmm.....

Anyway, I misread/misconsidered your question.

Assuming you're talking about installing CEDAR shinmgles on your walls...NOT asphalt...here goes:

Here's a web site which is the authority on all things cedar roof and walls:

http://www.cedarbureau.org/

Whatever else you do, it's wise to install flashings at all windows, doors, etc, as you re-side.

A roof CAN be your "friend"...rather than "that thing you hate".