Contacting a Company After Submitting Application?

Dear Experts, I have applied online for a position. There was no contact person named. Is there a good way to try to follow up? I have found some HR recruiting people for the company online. Should I try to contact them in anyway? Also, what is the protocol? If they don't specifically say 'don't call us,' then when should I call and who should I try to talk to? Our Twitter Advice Project (T.A.P.) is no longer an active campaign. To find an answer to the above question, please use the "Search" box in the right-hand column of this website.