If you are going to use online advertising there are many specialist sites who have various costing structures. Many discount the price of an online advert for a first time business user and have combination packages which include CV data base search and Multiple Job packages. Some of the sites have sophisticated online back room candidate management tools which help you keep track of and short list candidates as applicants submit their details.
Generating a broad response from candidates who meet your Job Specification criteria is the aim of any recruitment campaign. If you are overwhelmed with applicants you can be strict on progressing only those applicants who meet both your essential and desirable criteria. If you need to cut down your short list further prioritise those who live local to your work location or have additional experience or skills which may be of benefit as the company grows, or provide cover in times of sickness or holidays.
A good technique to pick the best site on which to place your job is to pretend to be an applicant and Google the type of position you have vacant from the location the job is to be based. The job site you are directed to at the top of the Google listing is probably the one which most of your potential candidates will be directed to. This exercise can also help you understand how the website matches candidate requirements to the jobs which are posted, if you are unsure ask the Job Site sales team how to maximise traffic to your job by manipulating key words in the advert.