any ideas on the best way to learn Mandarin?

[LexiSan]

For pronunciation, Pimsleur helps a lot. It is not good for actually learning the language, though. It does not offer enough vocabulary for that. Its method is effective, but you don't really "learn" the language as much as you learn to parrot phrases in response to certain questions or statements. I still love the program, though. Like I said the method is effective. It is a good starter and it's good for pronunciation. You can also find the transcripts for the Pimsleur lessons online.

If you're willing to buy textbooks, I suggest using Integrated Chinese published by Cheng & Tsui. The textbooks are great and the concepts are well-explained. The workbooks are also great. But be sure to buy the audio as well.

For memorizing vocabulary and grammar points, I recommend that you use an SRS program like Anki or Mnemosyne. Both are free programs. Anki has more features but I love Mnemosyne's simplicity. You will be fine with either, so pick which one you like best.

You can also try taking online classes. http://edufire.com comes to mind.

To practice writing, I recommend using http://search.twitter.com to search for those hashtags).

As SUPPLEMENTS, I suggest you start listening to some podcasts such as http://popupchinese.com If you subscribe you can get transcripts for the podcasts, which is nice. PopupChinese doesn't really have different plans, but for Chinesepod you can sign up for a basic plan and get the transcripts, which is really all you need.