The subnet calculator helps you design networks by taking an IP address and network mask and returning information such as network, broadcast address, and host range.
One of a set of tools we're offering as a way of saying thank you for being a part of the community.
I highly recommend, getting
Professional PHP Programming by Wrox even for newbies.
Then your ultimate friend while coding PHP is ofcourse the manual.
Check http://www.php.net/manual/en
Then you have very good sites having great articles/tutorials.
My fav. are,
http://www.phpbuilder.com
http://www.devshed.com
and yeah to learn MySQL, I would again recommend devshed.com.
Hope it gets you started,
JD