I have a little herb garden in my back yard, but I don't really know how to use herbs. Can you give me some pointers?

In general, I find herbs to be a very misunderstood means to a delicious end.  They can smell so distinct, and it seems as though it would be simple to impart their aroma to a tasty concoction, but often the only perceptible trace in a final dish is specks of green.
Herbs act a variety of ways in different situations.  Overall, you can roughly determine the best method for using a specific herb by the stem:

"The sturdier the stem, the longer the cooking time it can withstand."**

The best way to think of more delicate herbs (AKA fine herbs or herbes fines) is as tea for food.  With tea you don't boil the water with the with the tea itself in the water.  You boil the water and then you steep it for a few minutes.  The same goes with herbs - say you're cooking a tomato sauce for the fine purpose of tossing with spaghetti.  If you add in basil leaves early in the process, they can be almost imperceptible in the final product.  (though, I would like to point out, not completely without purpose.) However, if you wait until you are tossing the hot pasta with sauce to fold in some basil, the aroma of the basil will be much more prominent.  
Also, consider this: just as with freshly ground coffee, when you chop a fresh herb and add it to hot food, it can smell amazing - this is the point at which you should be consuming it.  The smell of amazing is the herbs yumminess escaping into the air.  So, with finer herbs err towards the end of the cooking process.  

Sage roasted chicken

Thicker stemmed herbs, such as rosemary and thyme [and sage despite it's softer stem] can withstand heat a little better.  Add them to roasted vegetables, potato gratin, and stocks and braises. (and know they'll still stand out more if you wait until the last hour or 30 minutes.)
I love to stuff sage and butter under the skin of a chicken and roast it.

AND keep in mind that this advice is for cooking herbs.  Any herb can be used raw (with varying degrees of delicious) in room temperature or cold food applications.


**The exception to this rule is sage, which has a more delicate stem, but can handle some heat.