Learning Traditional first with the goal of learning both I found this in the Mandarin wikibook:

"It is considered easier for people who learn Traditional to read both sets than people who learn Simplified only, but Simplified characters are less intimidating for beginners. In this wikibook, all examples and vocabulary are given in both systems, and you are encouraged to choose one system and stick with it throughout".

I found it to be potentially very valuable knowledge, so I started prodding around with a search engine only to find mass loads of Traditional vs Simplified web pages, which don't make me any more enlightened. What I'm interested in are facts that can help resolve the problem of which writing system I should learn first (or if I should learn both in parallel?), such as: What portion of people use each system? What portion of literature uses each system? How much easier is it if one learns Traditional first. I have learned which parts of china use each system, but cannot find these numbers and facts.

I have started learning Mandarin by myself and my goal is currently as vague as "wanting to speak Chinese". Being restricted to the last 6 decades of literature motivates me to know Traditional, but at first, Simplified seemed like the obvious choice. Of course, I don't know what weight to give these facts in my decision making, hence asking here.

I understand that I haven't asked a clear, single question, but I think it's clear what I'm trying to figure out.

谢谢
This is a difficult questions, since most people are quite religious about this topic. For some reason they prefer one over the other and say this one is the best one to learn first.

Learning Chinese characters takes a huge effort and most need many years for that, however once you know one set learning the other one is relatively easy.


  Wiki says that the Jianhuazi zong biao lists 350 individually
  simplified characters, 132 generalisable simplified characters and 14
  simplified radicals. All other simplifications are simply variation of
  the latter two simplifications (thousands of them, but applied in a
  standard and predictable way), or standardising on a more simple
  variant in place of a more complex variant of the same character.
  
  This means that there are 500 characters that are significantly
  different between the two sets, and the rest appear to me to be easy
  (e.g. 説 = 说, 錢 = 钱, etc.)
  
  So the extra effort one needs to invest into learning traditional
  characters after knowing the simplified set (or the other way around)
  amounts to learning about 500 characters. Since one should aspire to
  knowing about 3000 as some sort of arbitrary standard of literacy,
  this doesn't strike me as a huge deal.


Source: http://www.chinese-forums.com/index.php?/topic/14713-learning-hanzi-the-eternal-dilemma-of-simple-or-traditional/page_st_20_p_150151&amp;#entry150151

Also take a look on this page: http://www.chinese-forums.com/index.php?/topic/25651-learning-traditional-characters-after-studying-simplified-for-4-years/#entry214033

The 10 hours mentioned on the last page is a bit optimistic, but it is certainly quite manageable once you already know that many characters.

Also more or less all educated Chinese from the mainland can read traditional characters, and more or less all educated Chinese from Hongkong and Taiwanese people can read simplified characters. Not because they explicitly learned them, but due to exposure for example as subtitles from movies, songs or the internet. Once you have reached a certain level it's not that difficult.

What to choose first depends on your personal situation. I would first study what you think you will encounter most. For example if you often plan to go to Taiwan or Hongkong or especially want to view Taiwanese or Hongkong soap operas or movies (while learning Chinese most people are better at reading than listening, so the subtitles are of huge help) or have friends from Taiwan or Hongkong, start with traditional characters. If you on the other hand think you'll more often encounter simplified characters, choose simplified characters.