1. You should be willing to discuss issues surrounding the former pastor's exit. There are legal concerns obviously - particularly where there are churches and pastors who have failed to handle an exit in a biblical fashion. A violation of confidentiality can create a cloud of suspicion on BOTH parties. I get that. But you need to be prepared to be as transparent as you can when asked by a candidate. "There were some personal problems involved that we cannot talk about because of a confidentiality agreement, but you can rest in the fact that we handled things as spiritually as possible." Obviously there are two sides to every story, and if you handle YOURS correctly, you shouldn't be upset if he checks into the other side of the story. If everyone handled things according to the Bible, this wouldn't be an issue. But I digress...
2. You should put a copy of the budget in the candidate's hand. A lot can be said about the things a church values by looking at how it spends the Lord's money. There he will see your heart for missions, your level of indebtedness, how you pay your staff, the projects you currently have going. If you have a big pile of money in the bank and you aren't doing your share to support external missions - he will see that. If you have very little money budgeted for the youth or for CE or whatever, he will see where your heart is. He shouldn't have to ask about salaries and other benefits... you should have all that available early in the process.
3. You should avail him to your church stats/attendance records. He can see if you have been in decline and for how long - if you are growing or have plateaued, etc. Sometimes an outside pair of eyes can identify what the problem is and can offer you wise counsel whether you hire him or not. Think about it: if you have plateaued and one candidate has some insight to help you possibly overcome that, wouldn't you WANT that information? It might even be THE THING that provides needed clarity on both sides of the decision process.
4. You should give him a copy of your constitution and by-laws. Here he will learn things about the leadership structure that might provide clarity - "Who will he report to?" "How much notice should be given in the event he is asked to leave OR if he feels led elsewhere?" He will learn about the committees and meetings of the church, fiscal restrictions regarding how much money can be spent without a church vote, how a church views the ordinances and the practice of them. He doesn't know much about you and your operation and may not know to ask on the front end.
5. Let him know about those "immovable objects" on the church calendar or in the budget - in other words, those things that are so much a part of your identity as a church that you don't see changing them. For instance, if your church has a Christian School ministry, he needs to know your passion for it, your expectations regarding his relationship to it, and how that ministry might impact facilities, monies, and the churches ability to draw from its pool of volunteers. Some church members might work in the school and might see THAT as their ministry, making themselves off-limits to the church's mission. There are other things like campaigns, days of emphasis, church-trips, habitat for humanity, etc., that churches place a high premium on keeping and their staff supporting. He needs to know about these things BEFORE you hire him.
6. And finally, you need to convey a thought out job-description for him that he might use as a measuring rod of his work and ministry. He may not know he is expected to preach at the Nursing Home once a month because of a commitment the association has made to it... he might not know the church has had a radio ministry for 30 years and that he must handle all the aspects of it... he might not know you expect him to make a certain number of visits per week - or the opposite, that you have OTHERS to do that so he can study and see to administrative duties. A failure to communicate always makes for a rocky start. Let him know the things you want him to do to keep confusion to a minimum and watch how God will prosper this relationship!