HTML is easy to use. So easy, in fact, that almost anyone online can, and does, get involved with it to some degree at some point. The problem is that so many beginners don't learn enough about HTML (ever) to really understand what they are doing. Many just copy and paste from examples provided by others and hope for the best. The ultimate result, however, is a lot of very bad HTML on the Internet. And that bad code gets shared and copied over and over again!
There are a lot web-based of tutorials available and even more advice floating around in help forums and by email. The biggest problem is that a lot of this information is also bad. And, thus, an even bigger problem develops: explaining how to separate the good from the bad.
In order to recognize good HTML, or any HTML for that matter, you need to know what HTML is and how to use it. If you are reading this document you must, by definition, know what the English language is and, reasonably, how to use it. But is the language you speak and/or write good English or bad English? Just because you have learned the language through practical application and/or some formal schooling doesn't mean you are going to be using it correctly at all times. Wikipedia, speaking about programming languages, uses English as an example to explain how English can be used correctly and yet still be bad.
"Using natural language as an example, it may not be possible to assign a meaning to a grammatically correct sentence or the sentence may be false:
In the same manner we can create HTML that is perfectly good in the sense that it is well-formed but it may be meaningless or otherwise improper in terms of the usage. For example, HTML is an open language thereby allowing for the addition of new tags over time. In order to accommodate for this, and keep existing programs functioning in the face of new tags that may come along, any tag not recognized by a web browser is ignored. Thus, this code:
<alt name='content here'>Some Text Here</alt>
is completely correct but, since there is no alt tag at the time of this writing (despite claims to one by many self-styled HTML gurus posting in forums), it is also bad code. Whatever was intended by the inclusion of an alt tag will not occur when displayed in any current browser.
In order to code correctly you need to take the time (only a little time!) and truly learn HTML. It's really not difficult. There are only just over 100 actual HTML tags in total, and you will likely only ever use about three dozen of those, so it isn't an insurmountable task at all. There is a good online course on using HTML to create listing templates for selling on venue sites like eBay. The course can be found here. If you contact the instructor by email at: email@example.com and tell him you are a member of the Online Selling Association and want to take his course he will send you the access code for free! The course is about listing templates but it teaches some great HTML techniques that are transferable to any basic HTML coding you might do. It's a great place to learn how to code right.