can you help with launguage problems?

the problem is I use a lot of slags when i talk and they even reflect in my written work .This problem has to be solved since i want a more formal/professional language which will certainly help me later in my life. It will be very kind of you ppl if you can suggest me something to improve my language and make it a little more acceptable.

As far as reading books is concerned i read alot of them but not the literary books ...i read work of paulo coelho, dan brown, Dr.Brain wess

and others . And suggestion of some literary work could really help !

thanx (thanks ) in advance ;)