OK - I thought I'd read somewhere about configuring a Speedtouch 330.
If you are worried about being secure (I am), then I'd get onto eBay and buy a one piece modem/router. If you may want to use wireless internet round the home, then for a few pounds more you can get a WiFi one.
Something like a Netgear DG834 is plentiful so there are likely to be lots on eBay. Make sure it's a modem/router rather than a USB device. If it comes with the instruction manual, that'll save some Googling!
Linksys are OK too. Draytek are excellent but a bit dearer.
Check that it's a "telephone" rather than a "cable" modem.