Question: I have now built up a small portfolio of pencil/charcoal drawings. Most of the time they are kept in my folders, but sometimes they are viewed by friends and relatives. And on the odd occasion displayed at the local community hall.

I've started to notice finger marks and tiny smudges on the artwork. As none of pieces are permanently displayed I don't want to frame them.

What is the best way of preserving and protecting my pencil/charcoal art without having to put them behind glass?

One of my friends said that you could use hairspray? Is that the right way to go?

Answer: 
Using a fixative, as described in previous answers here, is a standard way of protecting one's own work. On an acquired piece, you're free to do whatever you want with your own property. However, it would likely negatively affect the market value or historical value of the piece. On a valuable or historical work, fixative might be viewed similar to "vandalism" since it changes the nature and likely the appearance of the work from what the artist created.

Acquired works should be stored in acid-free archival quality flat files between layers of special paper or else professionally framed behind glass.
I remember when I took art lessons when I was a kid. We would spray are drawings with non aerosol hairspray to keep them from getting smudged