Tokki:

1. I am an old man (76) who is also interested only in reading Chinese.

2. I can now read easy news articles if I have a good dictionary. (I still cannot read technical or scholarly articles.)

3. Each day I visit the website of a very respected European news website. (I don't think that I can mention its name here.) I find an interesting article and print it out so that I can slowly translate it.

4. I suggest that you learn traditional characters first.  Then it will be easier to guess what the simplified characters mean.  If you learn the simplified characters first, then it will be very hard to guess what the traditional characters are.  But if you do not have time to learn both, then I guess that it would be a good idea to learn the simplified characters.

5.  Here in Los Angeles, there are about five daily newspapers in the Chinese language. I believe that Mandarin-speaking and Cantonese-speaking people can read the SAME newspaper. For example, when I read Eric's post, I pronounced the characters to myself in Mandarin. I guess that a Cantonese speaker would pronounce them in a different way. 

6. Whenever you need help, you can post your question on italki.  A few days ago, an italki member helped me translate some characters that I had seen in a magazine.

Good luck!

It all really depends on what you want to do with the language. 

If you want the language that will allow you to speak to the most Chinese people, learn mandarin. If you're unsure about "which chinese" to learn, start with mandarin. 

The other dialects are interesting from an academic perspective, or for a specific purpose
a) You have Cantonese speaking friends
b)You like Hong Kong Cinema
c) You are interested in the history of the Chinese language
d) You want to shock Native speakers when you whip out some rough working class Shanghainese.

From the perspective of someone who has studied a few languages from an English speaking background, I will make three points. 

1) "Traditional" Chinese is harder to write, but understanding the history of a character often makes it easier to comprehend/remember. Simplified is most used in the mainland. http://en.wikipedia.org/wiki/Simplified_Chinese_character

2) Chinese (in general) is a very aural language. Listening and understanding the general "feel" of the language will really help, even in writing. This is true for most languages. 

3) Asian languages are not like western phonetic languages. Learning the characters will take time... usually years, to complete. (There are around 3500 commonly used day to day characters for simplified chinese, by conservative estimates.)

Your best bet is to learn characters simultaneously with your verbal/vocab/grammar skills.  
There are a load of great *free* resources out there for learning Mandarin, offered by the Chinese government. (hanyu net)

Good luck. It's a great fun, and extremely rewarding language! 

For most people who want to speak or listening Chinese, Chinese and Taiwanese (traditional chinese) have no critical difference . I may sum up the difference resembles British english and American English. Once you can listen and speak any of both , you would not have any diffficult in speaking or listening to another language except some slang . American , Australian or British english exist trace difference while you can ignore it in most situation .For instance, I have been learning english for 10 more years and I used to listen to American English more . In recent years I need to sit IELTs test , so I  have to  listen to British pronuncation more. No matter you learn from a Chinese or A Taiwanese , you do not need to worry about mutual communication between 2 peoples.

In terms of writing , It is a serious problem indeed . If you want to go deeper into Chinese culture or literature, especially China history and old relics, You had better learn traditional chinese because most current simple chinese characters are quite different from old traditional words. The current simple Chinese exist no more than 60 years. In other words , you cannot read it smoothly , the article which published 70 years ago .  Furthermore, Traditional Chinese are created more logically than simple chinese . that is why James suggest you learn traditional chinese at first . After you have learned Traditional Chinese, it is absolutely no problem to read simple Chinese at all.

普通话是官方语言，Cantonese和Taiwanese其实也是汉语，也许是因为距离太远（这个具体原因我并不清楚）导致了同样说汉语的人有着不同的发音。比如说我，我住在中国东北部，这里的人们说的话可以说最接近普通话了，可是我们说话还有东北方言。

3) Mandarin uses two writing systems:
Traditional Characters/正體字 (since the 5th century, so it is 1600 old now)
(now used mainly in Taiwan mainland, Penghu islands, etc. and North America)
and
Simplified Characters/简体字 (since 1950s, so it is 60 years old now)
(now used mainly in China mainland, Hainan island, etc. and North America).
Cantonese uses one writing system: 粵字 (since 1910s or so).
Taiwanese uses one writing system: Tâi-lô/台羅 (since 2006, derived from Peh-oe-ji or POJ, which became known in Taiwan in 1880s by medical missionary James Laidlaw Maxwell), but Taiwanese language is subtitled with Traditional Characters on TV.

4) Mandarin is the lingua franca among people who speak either of Cantonese and Taiwanese throughout Mainland China, Malaysia, Taiwan, Singapore, USA, Canada, etc.
Modern Standard Mandarin has several dialects now,
such as

Singaporean Mandarin, which is influenced by Southern Chinese dialects in a way;
Malaysian Mandarin, which is influenced by Malay, English, Hokkien/Min, etc. in a way;
Taiwanese Mandarin, which is influenced by Japanese, Taiwanese/Min in a way;
Putonghua (Mandarin), which is influenced by Northern Chinese dialects in a way.
But don't worry, these Mandarin dialects are mutually intelligible. Though, we as Mandarin speakers can (at least, I can) identify (at least, have a good guess) where you arte from as soon as we hear your accent :-)