I love learning Japanese, but one of the most frustrating things about it is that you can't really read it if you are a novice to practice. About how many kanji does it take to understand most, say traffic signs and advertisements?

If you really want to be able to do that then you need to just accept that the offical 2000 kanji need to be learnt. You could try and do it by frequency/usefullness, in which case following the japanese school grade lists would be best. I think most people on this forum would agree that this is pretty tough as you don't have any methods to learn the kanji other than by rote.

Much better to just knuckle down and learn the kanji through the Heisig method. Spend a few months doing nothing else and then you won't have to worry about them again!

It's recommended by Heisig, and justifiably so, to not worry about reading until you have the needed Kanji memorized. You cannot really do the AJATT method without knowing basicly all the Kanji as many sentences will contain the spread of what Kanji you need to know. For now, I say just learn them all.

So what to do if you want to learn both? Well, it's beyond the scope of this site, but perhaps in the future a website will be the saviour to learn both Kanji and the reading of it at the same time. Anki categorizes all the Kanji you put into your cards. Well, what if a website can take that Anki list of Kanji and develop the all the base Kanji and primitives you need to know to learn these. Ex: A reading card I input says "The time is 4 o'clock" (時刻 は 四時 です。), so that sentence activates Sun, Buddhist Temple, Soil, Glue, Drop and Measure for Ji, Human legs and Mouth for Yon, and Tophat, Coccoon, Person, and Saber for Koku. So, I'll have those kanji cards activated and learn them prior to worrying about the reading cards.

Now, is there a resource that creates a Kanji list of primitives and base Kanji from a list of Kanji you input? I don't think so. It would be a cool resource. Imagine starting off with Tam Kim's site, putting the kanji list he gives prior to each practice session. You get the benefit of learning Kanji and a morale boost of putting it to use. However, if such a site comes along, I say go for it and post the results.