How difficult would it be to make http requests with microcontroller via mobile 2g network?
How much extra parts are required to connect to a mobile network?
Can anyone point out tutorials or other pages discussing that topic?
The difficulty depends on what device you use to connect to the mobile network.
Wavecom modems made in the last few years have tcp/ip support in the modem, you can make a single http connection by sending a simple command over a serial connetion.
A cellular modem from years ago requires you to implement PPP and tcp/ip in your microcontroller.