Just questions to ask yourself...
What kind of sign shop are you?
Do you have a process already in place that would include an efficient use of a salesperson, including ways to quantify the efficiency and progress of the salesperson? (sales/contact sheets, reporting progress that is trackable)
Can your shop handle adding 2-3 times the workload you currently have (equipment, design, production, fabrication and installation)?
Do you already have quality marketing and collateral in place to get a salesmen up and running?
Looking for experienced? Or newbie?
If new to the business, do you and your staff have time to train someone?
If the Salesperson is new to the business, do you have a list of prospective clients and a way to maximize returns on cold calling? (Dodge Report, construction leads, media outlets that report new projects, construction and real estate managers contacts)
I am used to the slightly higher end of the sign business (wayfinding, environments, projects in the 100k+ range) and as a designer and project manager role. I deal with salespersons constantly. After having discussions with quite a few, knowledgeable salesmen get 15% of the complete job (before taxes) and get transportation cost and communication reimbursed. The salesmen usually project manage the project through the entire process. Updating the client, and all the players. These guys come in with clients already in there pocket... the only problem is, they can take the clients with them too. Most of these guys bring in a min. of a million a year.
I have a few sign shop clients where they are full service. Monuments, channel letters and miles of vinyl are their specialties. One guy I recently talked to seems to be the norm around here. He started out 3 years ago. He gets travel and communication paid for, he handles only the client communication, knew nothing of the sign business prior to coming on board and started with a tiny salary (I think he said 2k a month) and gets 10% of the complete project (before taxes). He was supplied a microsite so they could track his progress, cell phone, a laptop and iPad, and brochures to hand out. I supplied him the prospective client list and ways to find local clients needing signage so that way it maximized his cold calling prospects. The guy is a nightmare to work with (he thinks he learned the business in a matter of weeks, he art directs, he attempts to understand codes and fails miserably, he does not have a full grasp of the process) but he has an excellent work ethic and is bringing in enough work to eek out a modest living. He started out stumbling at first till he understood the product, now he's getting larger apartment projects in the 50-100k range and the occasional monument and electrical sign. I estimate he's selling just shy of 4-500k a year now from the looks of the drawings I am sending out. This is Orange County, CA... You can not live on 60k here if you have a family to take care of so your percentages may differ depending on your profit margin and cost of living.