I get the impression that he is not in the scene but you are? If this is the case then it is likely that he has no idea how to train you. How can he train you if he does not know how or what to train you in? If this is the case then the suggestions about books, DVDs, web pages etc above are useful as you can then learn together.

I also assume that you have had a frank and open discussion with him about your needs and wants and desires? If not, do so. If that is hard, suggest a game... you each take some time to write out your greatest sexual fantasy, in detail. Then you each read each other's, promising to have an open mind about them, and discuss how you feel about them. You, of course, will write down about your desire for slavery and this may give him a clue. You should also pay attention to what he wants - as a good slave should.

An extreme possibility (which you may or may not be brave enough for) is to give some undeniable signal that you are willing to serve him. Find a time when you have a lot of free time (an afternoon and evening for yourself, an evening for him). Clean the house, prepare a nice dinner and dress yourself appropriately - you can be totally naked or wear something suitably submissive. When he gets to the house (whether it is your shared house or your house you have invited him to - make sure he has no idea what you plan, just tell him you have a surprise) let him find you kneeling in the room, waiting for him with a drink ready. Spend the evening serving him, be perfectly submissive, let him eat first and ask permission to eat from him when he has finished. Ask how you should eat your food. When you have eaten, offer him a foot rub, back rub or some other service. When you leave the table and go to the living room, kneel at his feet rather than sit on the settee. Basically, let him see how good it can be to have you as his slave. If he seems uncomfortable with any of this, you can try to reassure him and see if he settles into enjoying it. If, however, he is totally freaked out by it, then its possible that being a Dom is not for him. Whatever the outcome, make sure you get a chance to talk to him about it afterwards so you can both assess your responses to it. If he likes the idea of being your Dom then you can discuss your rules and limits and so on using the expereince as a baseline - if he likes you kneeling at his feet, for example, but not eating your food off the floor then you can adjust things accordingly. Equally, if there was anything you didn't like about the experience then you can tell him this as well. Training is about learning how to serve a Dom but also learning what you yourself enjoy and do not enjoy.