If you want to do it from source i'll tell you how... go to http://www.apache.org
and download the apache source (i'll refer to apache 1.3.2 as i believe its currently more stable than 2.0). Now tar and unzip the source
tar -zxvpf apache_1.3.20.tar.gz
now change to the apache_1.3.20 directory and even though you should probally keep this at default your first time, in the future you want to edit your apache_1.3.20/src/Configuration file to include only the modules you want.
Now like i said you should ignore editing that file your first time and just go ahead and now I'm going to use /webroot as your apache server root
from the apache_1.3.20 directory, and that will configure apache with /webroot as your server root.
Next you want to compile (i think thats what its called, i suck with the terminology) so:
from your apache_1.3.20 dir and you have a compiled apache server, all thats left is to get it to do what you want it to and run it so now...
and edit your httpd.conf. Your httpd.conf file gives your server all the paramaters it needs in order to run such as your document root, if its has virtual servers, where to execute cgi from, etc. I'll leave this up to you as its all fairly simple, but if you run into any problems just leave it at its default.
Once you finish editing the httpd.conf file all thats left is to run httpd which you do by
and there you go, your own web server. You can test it out by doing
and you should get a page that says If you see this page then you've successfully installed apache.
Some good references are
to find out what each module does and also your INSTALL file in the apache_1.3.20 dir on of course how to install apache.