well, if you want to reply quickly, at the bottom of each post there are a few little buttons, "Quote, Quote+, reply, and Thanks." if you want to quote the person above you or a person anywhere on the page, click one of those first two buttons (quote is for text only, quote + is for text and pictures, smilies, etc).
Reply is for straight replies without quotes.
Thanks is for thanking people
If you want to add smilies or other more involved things to your reply, click "Post reply" right below the last post in a thread. The post reply button is on the far left and it's in red and purple.
I hope I said all of that clearly enough and I hope you find everything ok!
The last time I used this site when someone answered your post you would get a e-mail message that you have been answered. This time I did not get the message so I had to hunt for my post and click on it to see if I was answered. Is that the way it is done now?