I've got a fabulous book called Braiding Manes and Tails by Charni Lewis, ISBN 978-1-58017-699-6, Storey Publishing. It's incredibly clear and easy to follow and covers over 30 basic braids. It's also hard cover and very robust and has a drilled and bound hole right through it so you can hang it on a hook in the tack room while you practice!!! I got mine through the Equestrian Book Club and it was £4.99 but dunno how much it would normally be: Book Club stuff is a little cheaper than normal.
Even the best illustrated book in the world won't create a well plaited tail....unfortunately it just takes lots of practice and patience (oow and a good tail, that always helps)
but yes a few pics will certainly help you on the way.
Tell me about it!....if you find the answer...let me know!
I can plait my friends horses tails to perfection, tight, fine, very neat, but try to do it on my own horse and its looks like I've attempted it after 2 bottles of wine with a pair of shades on!
Sometimes the hair is shorter and finer at the top which makes it difficult .....thats my excuse anyway!