depends on what you need to be done. We had the line from the house to the tank replaced (terracotta to pvc) if you just need a clean out and your not backing up in the house yet I would suggest using a product called Bio-Clean www.alabamabioclean.com I think is the address its a really good monthly treatment for pipes and septic tanks. Its a natural bacteria and eats all the stuff.  
 
 
You can also go to www.home101show.com and there is a link on the page to Bio-Clean. the Home 101 show airs on Saturday am on 850am and 92.5fm it is hosted by Dave Billings of PenMark design and renovation, my husband and I have got a lot of tips from the show and its local so you can call in and ask questions. Dave also has an email address so you could email him and asked for a septic tank person that he would recommend.. or he will tell you what to look for in a good one.