Whether the person who marries you is a friend or a minister, this is your officiant. Each state has its own rules. Visit Virginia’s http://www.vdh.state.va.us/vital_records/marry.htm to find out theirs.
If the officiant is from another state be sure to call the Circuit Court in the county where you will marry for s/he may need to sign a petition and provide a filing fee.
A friend can marry you by getting a One-Time license. In Loudoun County the rules are:
To be a Civil Celebrant or One-Time-Ceremony Civil Celebrant, the individual(s) must reside in Loudoun County. A petition must be filed and a $84 filing fee paid to the Circuit Court. The completed petition will be forward to Circuit Court judge for his review and approval. Once the order has been approved, the petitioner must post a $500 surety bond and take an oath before the Clerk.http://www.loudoun.gov/Default.aspx?tabid=3645
Information about the decision process when selecting an officiant is available at
the National Association of Wedding Officiants: http://www.nawoonline.com/tips.htm
and from Martha Stewart: http://www.marthastewartweddings.com/article/hiring-a-wedding-officiant?czone=planning%2Fengagement-cnt%2Fget-organized
and from Brides.com: http://www.brides.com/wedding-ideas/wedding-ceremonies/2006/12/civil-ceremony-success
and from ezinearticles: http://ezinearticles.com/?Selecting-an-Officiant-For-Your-Wedding-Ceremony---What-to-Know-Before-You-Walk-Down-the-Aisle&id=4316652
PS:
To obtain a marriage license see http://www.loudoun.gov/index.aspx?NID=1162