Installing from the source is not something which one will do very often,  with  yum  and  apt  installing softwares with a few clicks.

To install anything from the source, you first need the source code of the application you need to install. This generally is obtained as a tarball (.gz or .bzip2 )

For example consider an application LDTP and let the source be in the file ldtp.tar.gz. Then

hari@home :~$ tar -zxvf ldtp.tar.gz  

#The above command creates a folder called ldtp which contains the source code

hari@home :~$ cd ldtp

hari@home :~$ sh autogen.sh

#The above command creates the configuration files required to compile and install ldtp. The above command will display a long output checking for the availablity of the softwares required to compile the source code.

hari@home :~$ ./configure

#If you dont fine the autogen.sh and if you have a file called configure.sh, then you can give this command directly. Else give this after sh autogen.sh

hari@home :~$ make

#This actually compiles the source code. This produces a long output and might take some time depending upon the lenght of the source code.

root@home :~#make install

#If you want to install the software, then give a make install as root.

hari@home :~$ make clean

#Removes the object files created during the compilation process.