Your fence is an investment
Okay, you've dressed up your yard and spent all your money on landscaping and now you want to make sure the neighbors kids, dogs or deer don't destroy everything you've done. So you decide to our in a wood fence. Since you spent all your money you are now looking for the cheapest wood fence you can get. WRONG! If you are looking just to protect the yard go and get a wire mesh, chicken wire fence from Home Depot and put it in yourself. Wala… mission accomplished. However if you want to have something that does the job AND becomes an investment worth protecting then you install a cedar fence with Miterless wood post caps.
It is a well known fact that the first parts of a fence to deteriorate are the posts. They can deteriorate from the top and the bottom. To protect them from rotting on the bottom you should coat them with a thick coat of "tar" to prevent water from damaging them immediately. This will delay any water damage. THe tops will be damaged by rain and snow if not protected well. Use a Miterless wood cap or a copper or stainless cap. These can make your posts outlast your fence. Remember this is an investment.