Most recruiters agree that screening candidates is very time-consuming. If you really can't justify using an outside staffing service, here's some advice on how to climb out of the pile of resumes.
As anyone who has ever run an employment ad knows, screening job applicants can be exasperating. Streamlining the hiring process is difficult; that's why there are so many companies out there who charge good money to do it for you.
It may seem obvious, but efficient screening starts with specifying clear job requirements. Write the job description carefully and include all the associated duties. Separate the necessary skills from the helpful skills, and the soft (interpersonal) skills from hard (job-related) skills.
If you run a job listing or a take out an ad, make sure the minimum requirements of the job and the salary range are clearly defined. It might also make sense to specify what you don't want (no one without industry experience, for example.) Ambiguous job postings attract a broad range of candidates, many of whom may or may not be qualified for the job you need done. That may seem like the right tactic, but it actually makes hiring much harder. The reality is, you'll end up with far fewer qualified applicants than you expect, once you sift through all the untargeted resumes.