webalizer package installation

[albi]

> 1) How to install gd and png libraries? Can you provide me url?  How to
> check they are installed or not?

see below

> 2) I also want to install a JAVA on freeBSD. What are the packages
> requires, how to install them. I know pkg_add command.

see here for installing java on FreeBSD :
http://www.freebsd.org/java/

> 3) How to check what packages are install on the system and how to
> resolve dependacies.

try installing from ports :
http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/ports-using.html

running the command "pkg_info" shows you all packages installed