It looks like you're worried about jumping in at the deep end - don't be
I think all the available distros (apart from small Debian) come with Apache pre-installed. In the case of Fedora and RedHat, starting Apache was a case of typing
service httpd start. I made a post on setting up an Invision board forum which was also very simple at
http://www.linode.com/forums/viewtopic.php?t=510
As for sendmail, I'm not too sure as I've never needed to use it on my Linode. However, I do know that most of the distro's initially boot up with the process running, so I doubt it's difficult at all to get it working to your specification.
You might like to check out
www.webmin.com which is a free GUI (albeit a little plain) that should help you manage almost every aspect of your server, including apache and sendmail.
Failing all that, folks around here are happy to help
