The thing that most people should include is the actual cost for the design work should you decide to not purchase cabinets from them and want to walk away. Are you paying by the hour for time, or are you paying a percentage of the cabinet purchase in lieu of that. That design work can be anywhere from $250 on the very low side to 10K or higher on the high side. If you find that your collaboration isn't working, you need to know what you owe, and what you own. Typically, for the $250 range, you're paying for their time only, and not the design documents. They will retain ownership of those. Of course, if they haven't produced anything that you like, then that's a bit of a moot point in owning any of the design drawings.

You also need to include who is responsible for providing the site measurements, and the role of the installer in this. Typically, a KD may do an initial site measurement to get the ball rolling, but your installer will provide the final measurements after the construction is completed and the walls are up. And your installer should review the design drawings before the cabinets are ordered. Sometimes that is because the skill of the KD is greater than that of the installer, and sometimes, it's the other way around, and the KD can learn a thing or two from the installer. Either way, it's the partnership of the two that will create your kitchen. Sometimes the cabinet shop will have their own dedicated installers, and then it's their responsibility for the correct measurements.

If you are having custom cabinets done, be sure that you incorporate an actual door sample and finish into the agreement as well as the construction drawings. You need to both view and sign those before things go into production. This can take a bit of time, so getting in a hurry won't be productive on your part.

And that is another thing about setting the proper expectations on the front end as far as timing goes. If your chosen cabinet line has an 8 week lead time, and you are all over the map when it comes to design decisions, you're already too late to start this for a graduation party in May. You're about right for making a Labor Day party. Good work takes time. That means time for design work, construction, and all of the finishing touches.

3 months is about average for a kitchen remodel. Plus the lead time for the production of the cabinets. So, if your cabinet guy is 12 weeks out, you can bet that your remodel will take 6 months.

The best thing you can do on the timing front is to make decisions. And then stick with those decisions rather than second guessing yourself. People who know what they want and just need a bit of help getting it are my favorite clients. You can nail everything down in a single meeting, and then a final meeting and then order. A week to 10 days between the initial and the close. Easy.

When people start having decision paralysis because they can't narrow down their choices from the thousands available, that's when they need to lean heavily on their KD for assistance in narrowing things to 2-3 choices from which to pick.

Many years ago I read in "The Peter Principal": a contract is an agreement of mutual distrust.
That said mine is also simple. We get a retainer at the second or third meeting (I haven't seen a one meeting and out since I worked at Home Depot) By the time we ask for a retainer my clients know what to expect, which is why we wait. I'd gladly put anything within reason into the agreement to make them feel more comfortable. Unless of course I didn't trust them in which case we should be parting ways. I'm not sure how much of this NEEDS to be in an agreement BUT you should know most of the answers, so if that is what it takes....

To add Green's good advice:

Things you should already know-
do you trust them? checked references? what type of presentations can you expect? hand drawn, computer, color renderings? If color when in the process? how many variations do they present? do they schedule meetings, if so how? or do you wait for a phone call? how much time is allowed for meetings? will they come to the site more than just to measure?

is the retainer/fee applied to a purchase? when will you expect a solid ballpark? and what can make it go up? a solid final price? do they work with a total budget or just cabinet prices? can you walk away with just plans? does that entail an extra fee?

Things to think about-
major revisions- is there a limit and what costs are involved if there are more

changes after ordering (or late in the process) - can you , how much time do you have? what will it cost? (note this is the kiss of death, simply don't do it unless you want problems!!!),

Plans and drawings- who owns them, when can you be given copies, new construction will they work with architect/builder and supply them with plans? in what format? what kind of drawings and details are included?
Surfaces- are they to help with other surfaces?
Electric plans? do they do them?
Do they offer in house installation, oversee the project ? no matter who installs it?
Do you have a target date? is it critical? can it be done by then and what are your responsibilities in that?