Chinese pronunciation
Sounds strange and difficult? Certainly is. Not impossible though.
The first and essential thing to do is to master pinyin, the method of rendering Chinese pronunciation in western letters - ie the Chinese characters for China as 'zhongguo'. This romanisation is used for teaching Chinese to foreigners and elementary school children. Use it to learn to pronounce and discriminate between the different vowels and consonants - and do it well. This really is your foundation, and no matter how much time you put into learning words, if you can't make the sounds that go into them, you are going to have trouble. The majority of the sounds are pretty straightforward, though one or two will continue to give you tongueache and it will be a long time before you can hear the difference between 'qi' and 'ji'; or 'chen' and 'cheng'.
Chinese tones
They're horrible, I hate them. So will you. My own personal and untested theory is that it is pointless trying to learn tones in isolation (eg saying 'ma' repeatedly until you randomly hit the right combination, drawing praise from your teacher until she realises it was a fluke when you start on 'ba') as you very rarely say anything in isolation. Instead, I recommend that you learn tones in phrases, mimicing the 'up and down-ness'. I'd love to hear how you get on with this method, and if it works I might even try it myself.
On the plus side, I never paid much attention to tones, and apart from sounding funny and getting laughed at slightly more often than normal, it hasn't caused me any problems. Beginners are often told that if they don't learn the tones, nobody will be able to tell if you are saying 'buy a horse' or 'sell a mother'. My view is that Chinese people are intelligent enough to look and see if you are looking apprasingly at their horse, or dragging a woman 25 years your senior around with a price chalked on her coat.
I don't recommend beginners worry too much about tones - it's much more important to get your pronunciation reasonably good and then start building up useful words and phrases. If you think you might stay in China a long time, or are a perfectionist, then make sure you at least know what the tones should be, even if you can't get them right at first - the tones will be important later on when you are having more sophisticated conversations and presenting Spring Festival Galas on CCTV1