I agree that finding out what you both like is a good idea. You need to know what sort of sub they are and treat them in the right way. A quick and easy way to find out is one of the many BDSM checklists that can be found online, though these mainly deal with limits in sessions rather than lifestyle. A few suggestions for rules, however:

- As well as the hour long research above, make a rule that they have to write a journal either once a day or once a week or after every physical session you have. They can also write a summary of what they have researched in this journal. This can be in a proper paper diary or typed onto a computer and, if typed onto a computer, can be private (between the two of you) or public. Most live journal sites also allow you to share posts with only a select group of friends. Ths journal needs to contain all the sub's thoughts and feelings about the situation. Once it is written, you should discuss any issues raised in it.

- You can set rules about how your sub dresses and when/how they eat. These sorts of rules really need discussion, however, as some subs may not be able to follow certain dress/food rules due to health conditions or work based clothing rules. It is not a good idea to insist a sub eats bread if they are gluten intolerant nor is it a good idea to make them wear slutty clothes if they need to be 'business professional' for work. So, discuss these possible limits before imposing any rules like this.

- Behaviour rules. How to stand, how to sit, how to address another Dom/me, how and when they should kneel during a session or before a session starts. For these you need to distinguish between behaviour during a session (which is usually a private affair between the two of you), in 'scene public' such as at munches and play parties and in public. Basically, if you want your sub to do something like always approach you during a session on their knees then you add this to the rules.

- Housework. You can set rules about general everyday things like housework, time spent with you and so on. If you share a house, you can outline what housework tasks the sub is expected to perform and how often. If you do not share a house you can still enforce a housework schedule - at the very least making sure that the house is clean for when you arrive for a session and that all the toys are taken care of and laid out ready. You can also outline things that the sub can do for you personally such as massage, grooming, bathing and so on.

Now I am not saying that all of these apply to you but they are things I have seen in some Dom/me/sub relationships. You pick and choose what you like the look of and discuss these with the sub before outlining the rules in full.

There are some examples of 'slave contracts' online which you can look to for ideas for rules. Some of them are very simple (you will show proper respect at all times and follow Master's orders) while others are very long and complicated with a lot of detail (including one which included as a rule the requirement to memorise all 100 odd clauses of the contract for recitation). Do some searches and see what you come up with.