softlysoftly, I am not familiar with Logic so I may not be able to help you. If Logic behaves like any other host and you have called up Kontakt as a VST instrument you should then beable to load any instrument from your hard drive. If you are trying to run Kontakt as a standalone and use Logic as a sequencer then you need virtual midi cables (Midi Yoke, Maple, MidiOverLan, etc. to connect the two.

In general, you would load the files with extension *.nki. Kontakt uses other extensions as well but it may be best to learn with *.nki files. You can drag and drop these files into the kontakt rack.

Softsynths contrary to what others often think are easy to use and will give you more control over your instruments. If you acquire top of the line samples you will also get the best sound available.