I would find it most helpful if someone could point me in the general direction for what I am looking for. Allow me to briefly explain:
I am looking for a phone system that is very simple. Has all of the usual stuff like voicemail, call transfer and number directories but also allows me some control over calls from a programmers point of view.
I have used Avaya phone systems before and integrated them into MS Access/SQL Server applications using their APIs but they always missed a key bit of functionality. The ability to store the number that the caller has called AFTER an internal transfer - such as from reception to sales. I need it to help with monitoring advertising.
Although this in itself is not my question. My question is this - if I wanted to build a simple phone system based on Asterisk with API integration into VB/MS Access what hardware/software would I be best looking at? Ignore what you may think of Access at this point - I already know what you’re thinking 
- I just want a basic guide or starting point so I can take a look at the Asterisk system and see how easy it would be to integrate and what control I would get.
Thank you for taking the time to read my noob request - and Happy New Year too! 