Options

I originally posted my question in the ASX General Forum however given the options are related SRT I was hoping I may receive a reply here whilst we await the news.

I've been investing in shares for the past year but would like to expand to options. I'm absolutely perplexed however on how they work. Normally I'm able to pick up things pretty quickly but options are baffling me. I've read tutorials on the Commsec website and done some googling but am still none the wiser.

Specifically, I'm very interested in SRTOA due to expire in December 2017. If I was to purchase them on the Commsec website do I pay for them straight away, what happens in December 2017, how do I convert them to heads and do I get more than one head for each option?

Thank you so much to anyone who can help me out.