Using My Herbs

I have a small garden of just herbs that I plant every year. I have tarragon in it from last year and it is very happy in my garden. Is there a way that I can make home-made oils with some of the herbs, such as tarragon, parsley, sage, lavender and rosemary. Please tell me what I can make with these herbs. Would you dry them in an oven or hang them up to dry?

Since you say you have a small garden, I think making oils from them is impractical. You would need quite large quantities to distil the oils from them. You need a distiller, a device that consists of a glass tube inside a glass jacket. The outside jacket has cold water running through it and the inner tube is connected to a flask in which you gently boil your herb in water. The open end of the inner glass tube points into a container that catches your distilled oils.
You can make herb vinegars with all but the lavender. With the lavender dry the flowers to be used as moth repellent.
To dry any herb, avoid using the oven, since the heat is too high and drives out the oils leaving you with little more than hay. Hang them up in an airy shady place or place them spread out on a fly screen in an airy shady place.
There are many books available on the subject of harvesting and using herbs. Richters book list is impressive and I would urge you to consult it.