I'm trying to learn how to configure,make,install opensource projects in linux and have read some tutorials. what's a good opensource project to start with? Thanks.

As far as I understand your question, you want to learn how to use the GNU toolchain. Well, if that's the case:
1) almost any open-source project's source tarball is packed that way. Dowload SDL, for example. However, I don't believe you'll be able to learn a lot before you know what a makefile is.
2) I'd suggest that you should learn how to use scons, instead. It's newer, it uses Python instead of a bash-like (=> ugly, difficult both to read a write) language. The site has a good documentation, the man pages should be useful as well. I believe linuxdcplusplus uses scons.

You should do GNU hello world ofcourse.

Quote: I'd suggest that you should learn how to use scons, instead.

Scons is nice, but there are a lot of other tooldchains built around autoconf and automake. Debian packaging for example. RPM probably too.

Do you mean how to make and install a tarball?

After unpacking the tarball:

$ tar -xvzf fubar.tar.gz
$ cd fubar

You should find a file called INSTALL that describe how to make and install the source.
The normal procedure is

$ ./configure --help
$ ./configure
$ make
# make install

Note that the make install command requires root access.

A good place to find and download opensource projects is sourceforge