Namaste all.

I've become increasingly interested in Tantric Hinduism as of late (in particular the Kaula school, and the Natha Sampradaya), and I'm curious to know what text I should begin to study with? I'm interested in both left-handed (Vamachara) and right-handed (Dakshinachara) practices (though admittedly I'm a bit more interested in left-handed practices), so I'll gladly read texts followed by either tradition.