Ok.
1. You need to enter the URL by either:
a) clicking the "http://" button in the 'reply to topic' page, or
b) you can type (URL=http://ADDRESS GOES HERE)TEXT(/URL) but you will need to replace all the ( and ) with [ and ].
2. $50 is pretty cheap... do you get much downloads? careful with ISPs that say things like that, then hit you with big charges for downloads. Ask them how much downloads your allowed for the $50 and then what the charge is for any download after that. Then calculate how much you would download regularly.
3. The instructions for setting up chat are here somewhere.. I think in the pub, and their quite easy to follow (Thanks to DK) but you'll need to download mIRC first from
www.mirc.com or
www.download.com or something like that.
Good Luck!
