Starting out - Importing drum samples

I have downloaded the 30 day trial and am working though how to use the program. I watched an online tutorial that explains the basics of importing percussion sample files (i.e., ctrl P; ‘import’; and then selecting files) so that I can try to set up my own basic drum beat/loop, however I do not know which file type extension is supposed to be imported. Is it one of *.halpreset or *.vstsound? When I try to pre-view any of those files, the response is ‘Invalid or not supported file’ and I cannot drag those files into my workspace. I am using Windows 7, and Cubase LE Al Elements 8, 64 bit.
Thanks for you help.


Audio files are supported, i.e. WAV, AIFF, REX, MP3…