BBEdit 5.0 (Mac) and Macromedia HomeSite 5.0 (PC)
These are basically high-powered text editors like SimpleText and Notepad that have been optimized for writing and editing HTML code -- especially large amounts of code. They have all of the organizing features of a word processor like Microsoft Word, e.g. searching and replacing, spell checking, and sorting, but none of the formatting features - they are not at all concerned with formatting text for presentation on the printed page. These are what professional web developers are using. They make editing much easier and will save you time. If you have not done so already, you should obtain a copy for your platform and begin working with it as soon as possible.
BBEdit is developed and maintained by Bare Bones Software and, unfortunately, is only available for the Macintosh. The cost is about $100. You can also download a very, very limited free version from their website. Although the free version is missing many of the useful utilities, it is still a better editor for HTML than SimpleText.
HomeSite is developed by Macromedia (formerly Allaire - the same folks who developed Cold Fusion). The cost is about $90. It is only available for PC. Sometimes a free trial version available.