1. Put them on marketplaces like Sedo/Afternic etc.
2. Put them on Chinese marketplaces like 4.cn
3. Actively Call the potential buyers
4. Have patience
It depends, of course on the quality of the domains. Post or PM what you consider 10 of your best names, and I can give you my exact input on how and where to sell them.
So you say you've bought 1500 but you are just a beginner ?
I would say you can do nothing: you just wait for buyers to contact you. But the domains have to be good enough.