VERIZON VZACCESS MANAGER: (credits to Verizon Wireless support website, customized for Millenicom)
Connecting to the Internet is as simple as selecting the network connection type shown in the list of the VZAccess Manager and clicking the Connect button. Note that the Connect button immediately above the list will change to "Connect WWAN" as appropriate based on the current selection in the networks list.

1. Select the "NationalAccess - Mobile Broadband" connection.
2. Click the "Connect WWAN" button when it becomes enabled.

Once connected, the "Connect WWAN" button will change to "Disconnect". Simply click this to end your current connection.

SPRINT - FRANKLIN CDU-680 (MOBILE BROADBAND - CDU680DORA)
Open the "Mobile Broadband - CDU680DORA" application. Insert your aircard if it is not already inserted, and wait until the Connection Manager reads "Disconnected" in dark text and shows a signal meter to the right. To connect, simply press the gray "GO" button. A window that says "Welcome to the Mobile Broadband" [sic] will appear once you are successfully connected. Click OK.

SPRINT SMARTVIEW
This is about the simplest. Open the Sprint SmartView software and, on the Mobile Broadband tab,
click Connect.

T-MOBILE OPTION 452 - GLOBETROTTER MOBILITY MANAGER
Similar in simplicity to Sprint SmartView, except it's not Sprint, it's T-Mobile. Open the software, and when you're able to, click Connect.