Question about citizenship when marrying a British citizen

Hello
I got engaged last night!
I am in the UK on a work permit, have been here on the permit for a year. 
My company is extending my permit for another 2 years.
I was told by someone that because I am already here working, that all I need to do is get married and then pay the fee for the marriage visa and then I will be all set.  Is it that easy??

Yes, it's that easy! 

Hang on, MoggyMay from the title of your post do you mean will you get citizenship straight away? The answer to that would be no but you will get a spouse visa.

Oh - good point.  I assumed she was merely talking about being able to get married without leaving the UK.

As for citizenship, you'd still have to wait the requisite time - and you'll only be getting LLR when you get married.  After 2 years you apply for ILR and then after meeting the time requirements you can apply for citizenship.

can i work anywhere though and get nhs and all that?

Once you're married, yes, you can change your job and you'll be eligible for NHS (but not many, if any, other benefits, until you have Indefinite Leave).