You create the public_html directory, make up a nice, new index.html file, and go to view your site. Instead of your homepage, you see...
You don't have permission to access the requested object. It is either read-protected or not readable by the server.
If you think this is a server error, please contact the webmaster.
You failed to properly set file permissions. A recent change to the default user umask means that all files you create can only be read to and written by you. This is a problem on the web because other people need to access your files.
You will need to properly set all file permissions for folders and directories you create inside your ~/public_html/ directory. For example, the following web page is NOT accessible:
acs# ls -l
drwx------ 2 shy sysadmin 4096 Mar 9 15:13 directory
-rw------- 1 shy sysadmin 0 Mar 9 15:13 index.html
The only person who can read index.html is you, and the only person who can read directory/ is you. What you want to do is make your files and directories readable by others, as per the following example:
acs# chmod 755 directory/
acs# chmod 644 index.html
acs# ls -l
drwxr-xr-x 2 shy sysadmin 4096 Mar 9 15:13 directory
-rw-r--r-- 1 shy sysadmin 0 Mar 9 15:13 index.html
Now your files are readable (and directories executable) by others. Point your web browser to http://acs.pha.jhu.edu/~USERNAME/ and take a look at your functional, new web page.