From memory, that weather station is a rebadged Fine Offset / Watson model and good value for money generally (for what you actually get;-) ). I dont think you can really expand much on it though, and the windspeed is only read about every 15 seconds - so good as indicator, but that accurate. However, don't knock it, it's a great start.
As for software Cumulous is quite popular ( and free/shareware) and is easy to use. Many people prefer Weather Display as it's bigger and more versatile, but you do have to pay for it after a month. It's horses for courses though, if you're happy, stick with it.
I would suggest using this as an "intro" into weather, but be warned,,,,, it's rather addictive. Welcome to the forum!
woody