Here is a break down, of some of the tasks that are done by a Webmaster to build or maintain a website:

• Building a Web site from scratch, starting with a site map and templates.
• Coding the site, updating existing content and adding new content.
• Improving the site, with new content and features.
• Search Engine Optimization or SEO.
• Enhanced navigation, HTML links, Javascript and the use of CSS Style Sheets to enhance Links.
• Creation of artwork, logos, animation, streaming video and Sound.
• HTML, CSS, SSI, SSL, PHP, Ajax, Perl, JavaScript, Java, and MySQL data bases.
• Basic Site Navigation ( checking that all links are up to date and working correctly, this site has around 1700 links. )
• Installing Flash, Java and Javascript coding and have it MS compliant, "click to activate", coding to remove that user action.
• Installation of pre-existing Perl scripts.( Your Server needs a cgi-bin for these, the scripts are usually written in Perl. )
• Installation of pre-existing PHP scripts.
• Backing up the site to CD-ROM and Harddrive.
• Coding pages to be compatible with all or most Browsers.
• Create Special Error docs.
• robot.txt, htaccess, password protecting folders.
• Upload content to server, create folders and files, chmod folders, images and files to the correct permissions.
• A security note here: you should never, ever, chmod anything 777 rwxrwxrwx, r=Read w=Write x=Execute. Folders should be 755 rwx-xr-xr, images and files should be 644 rw-r-r, most software on the web is written with PHP right now and all PHP files can be chmoded to 644. If you want to get hacked chmod something 777 and you will get hacked, that gives everyone read/write and execute permissions when I say everyone I mean the Owner, the Group and the Public. If you run your own server and set it up right you can use 777, I am talking about a shared server, a Hosting Account.
• Making sure you spell check every page. lol visitors will let you know if you did not, they keep you on your toes, which is great, I like that feedback.
• Responding to visitors comments and concerns.
• A .com .net .something registered in your name.
• A Server to Host Website.

Some more complex Webmasters Tasks:

• Specially-crafted icons. (such as logos, 3D objects, or characters)
• Mouse-over interactive buttons and similar features.
• Standard GIF animations.
• Flash animation and have it MS compliant, "click to activate", coding to remove that user action.
• Java scripting and have it MS compliant, "click to activate", coding to remove that user action.

Tasks which are time consuming and some need Special Security Features:

• Dealing with Hackers, Spambots and Spammers.
• Setting up and Message Board. ( These are being targeted by Spammers and Spambots with a vengeance )
• Setting up and Securing a Guest book, these are targeted by Spammers and Spambots with a vengeance.
• Chat Rooms, you need a Server with a lot of Bandwidth for this and is very CPU intensive, should be on a special server.
• Setting up and Securing a contact or feedback form, again, any input form is being targeted by Spammers and Spambots.
• Setting up and Securing a Blog with comments turned on. targeted by Spammers and Spambots.
• Protecting email addresses. from Spammers and Spambots.
• Making sure all Scripts are up to date with Security Patches.
• Checking Error and Access Logs.
• Protecting files from Hackers.
• Setup email accounts

Tools that I use to build and maintain the Website:

• Dreamweaver CS5 and Notepad++.
• Adobe PhotoShop CS5.
• Adobe Flash CS4.
• My FTP client is CuteFTP Pro 8.
• ScriptForest Menu Maker, for my Java Menu, compatible with all Browsers, edit 4 files and upload them to the server, all pages are updated.
• To make my Flash Banners, I use Swish MiniMax 2.
• Remote Hosting Service, I have been using Branzone and I am extremely happy with them, the support is second to none.