I want to install a wvdial debian package on my Raspberry Pi Model B, Raspbian OS, to enable Internet access via a dongle. I am downloading the package on a different x86 machine and will later transfer and install it on the RPi. The download options are for different architectures. For Rpi, should I choose armel or armhf ?
You'll want to use armhf.
However, please note that by default, most Wi-Fi adapters work in Raspbian by default! Just plug it in to a powered USB hub (they usually need more power than the Pi gives out), type startx into a terminal to open the desktop, then open the "WiFi Config" app on the desktop.
