If you really have to have THIS name, search the owner on Google, check the archive to see if the domain has been used in the past, check estibot.com to get a rough idea of it's value. Somebody correct me, but I think you can get some hints how many domains he owns at domaintools.
Check the expiry in Whois - if it is about to expire then consider seeing if it will be dropped. If it has several years registration then it may not be for sale - sometimes a domain is used for email while the www does not resolve.
Once you have done your research send them an offer. In many cases you would need to get their attention with a three figure offer (or higher), but you also do not want to get them thinking you have money to burn. Don't give them the "poor student" line or other BS - if they see through it it would make things a lot more difficult.
If it is a three letter or other well known domain realize that the owner gets many offers and you would have to offer a lot of money to get his attention, or be very lucky with your timing.
The domain that is the category-killer for the small niche that I sell jewelry in was unused for three years, while I made do with the .net and a backwards .com. I sent the owner an email offering to buy it. I did not quote a price, but I was willing to spend up to mid $$$. He did not reply, but a year later he dropped it and I got it for $10 on TDNAM! So, if it is not a domain that everybody would want you might just keep an eye on it.
