How to build a bitcoin trading bot
Building trading bots that interact with the exchanges is very similar to interacting with other RESTful APIs. Basically, you make query objects to whichever exchange you like to use. Here is a simple example: https://github.com/AdamCox9/nickelbot/blob/master/adapters/poloniex/poloniex_lib.php

Nickelbot is development platform written in PHP that has all the boilerplate code for interacting with several exchanges. You can write a bot once, like https://github.com/AdamCox9/nickelbot/blob/master/bots/make_min_orders.php that will give you full control and it works with multiple exchanges.

Take a look at all the example code on https://github.com/AdamCox9/nickelbot to see exactly what you need to do.