What are those thingies I see some people with? Like they look like USB something or others that they put into their computer for Internet? I had a friend say that you just put minutes on it, like you would a cell phone?
The gizmo (or dongle) needs a SIM card in it, and has some memory that contains the software that needs to be installed onto the computer. When this software is installing you need to answer questions about the SIM card and similar. This link:
Small note about Indosat 3.5G Broadband with Modem Huawei E220 gives you some idea of what its like with one particular brand of gizmo, and Indosat as the provider.
I don't have one, but have borrowed from others at times and have found the link (in North Bali) to be very slow. Maybe, it's better in the south.