VBA Code no longer working

A few weeks ago, I had an issue which was resolved here. I was given a bit of code that worked perfectly for me. I had noticed when I tried to save my project, I got a message indicating that my project wasn't macro-enabled, or some such. Like a fool I just disregarded it and thought I'd sort that out some time later. Each time I opened my project, I copy/pasted the code in. I know - not really the best way to deal with it. Eventually, I tried to save my file as macro-enabled with "Save as". It didn't seem to help. I was busy with many other things at the time, and it wasn't a high priority for me, so I kinda just blew it off.

Since then, I upgraded from Vista to Windows 7. Today, I loaded my old project, and (as expected) the code wasn't working. I saved it as macro-enabled, and still nothing. I opened the VBA page, and the code is there. But I can't get it to work. The code is unchanged from the original time I had applied it. I think the only change from when it worked is that the file is now saved as .xlsm (and that I use Win7). What do I have to do to have the code work again, and what did I do wrong to mess it up begin with? Should I or shouldn't I save my project as macro-enabled, and do I do that before or after I apply the code?

Thanks for any help.

PS: can anybody recommend a good resource to learn more about macros and VBA coding? A book or website? I can't seem to find much through Google.