• Dreamweaver snippets are your friends. Add stuff that you will use all the time, like paragraphs, list items, etc. As you get more advanced, you will also be able to store jQuery or JavaScript snippets that you don’t want to have to remember.
• Learn and use Fireworks. This is the web designer’s staple program. If you already know Photoshop, you won’t have a steep learning curve.
• Never use tables for layout. You probably already know this, but just in case. That is why you shouldn’t use Dreamweaver’s design mode (at least exclusively) to build a page. It generates terrible code. You can, on the other hand, use Dreamweaver as a code editor. It’s still what I code in the most.
• USE FIREFOX! I can’t say this enough. It has some absolutely indispensable web development tools, like Firebug. I don’t know where I’d be without it. You can actually modify the CSS and HTML, and run jQuery right there in the browser. If something is wrong on a page, you can zoom in on it and find out what the problem is. Love it. Chrome also has a similar tool, though I haven’t yet had a chance to compare it to Firebug.
• Get ready to be CONSTANTLY frustrated by IE6. It’s a horrible browser that breaks web pages all the time. That’s not an opinion; it’s fact. Learn how to hack your CSS to target only IE6. Get familiar with the most common IE6 bugs and their solutions.
• Learn jQuery! HTML, CSS, and jQuery (sometimes referred to collectively as DHTML) are going to be your main technologies. It’s tough at first, but CSS selectors are your launching point.
• If you have to branch into programming, learn PHP. It’s still relevant to the front-end development (a fancy term for web design), and it’s very common. I’ve picked up a bit by playing with WordPress, which is awesome by the way.
• Take advantage of Dreamweaver’s layout templates.

This are some big things I can think of off the top of my head.