Do you actually need a bespoke software solution?
There are lots of purpose built off-the-shelf software packages, built for a variety of businesses. It is well worth evaluating these as well as talking to a bespoke developer.
Your business comes first
When evaluating off-the-shelf software, remember that the software should fit your business, not the other way round. Businesses that purchase software, then adapt their processes to fit that software are taking the wrong approach.
What makes you think you need bespoke software?
Consider what you're looking to achieve. No point in buying software just for the sake of it. Don't buy software just to automate a single, possibly inefficient or unnecessary process.
Talking to a software developer:
Do they have experience in your sector?
A company whose experience is entire B2B are unlikely to be the best people to develop a solution for a B2C client and vice versa.
Set a realistic budget
Bespoke software is written solely for you, and should not be considered a cheap option. Whilst an off-the-shelf solution may cost £500-600, it is developed for the mass market and won't necessarily do everything you need it to do,and in the way you need to do it.
Dedicate time to your project
Almost every software development company will need to spend time interviewing your staff about their experiences and expectations of your existing software and the bespoke solution being developed. A thorough developer will gather opinions of everyone in the company, not just one person from each department. The input of everyone is important in developing workflow processes that the software will follow. The developer needs to understand what the software needs to do from the user's perspective as well as the perspective of management.
Be prepared to give additional input
Often, the development team working on your project will require further information from you as development goes on. It should be considered a sign that good progress is being made, and that the developers place importance on getting things right first time.
BETA testing is an important step
When handed a BETA version of your software, it is advisable to give copies to several members of your team, to allow them to experiment with the new software and provide valuable feedback as to the real-life usability and efficiency.