Install postgresql before proceeding with the below given info.
1) Download postgis,geos,proj4.
a) http://www.remotesensing.org/proj
b) http://geos.refractions.net
c) http://postgis.refractions.net/download/
2) Extract all of them and do a cd to proj4
3) cd proj4
$ ./configure
$ make
$ sudo make install
4) cd geos
$ ./configure
$ make
$ sudo make install
5) cd postgis
$ ./configure --with-pgsql=/usr/local/pgsql/bin/pg_config
$ make
$ sudo make install
6) set the path
$ vim /etc/profile
#add the followig lines
LD_LIBRARY_PATH=/usr/local/pgsql/lib
export LD_LIBRARY_PATH
PG_HOME=/usr/local/pgsql
PATH=/usr/local/lib:$PG_HOME/bin:$PG_HOME/lib:$PATH
7) Edit vim /etc/ld.so.conf
# add the following lines
/usr/local/pgsql/lib
/usr/local/lib
# run ldconfig
$ldconfig
8) Creating spatial data
> su - postgres
password: **************
> createlang plpgsql databasename
> psql -f lwpostgis.sql -d your_database
> psql -f spatial_ref_sys.sql -d your_database
