Need gas and oil mixing ratio for my jonsered chainsaw?

i have a jonsered 2149 49cc turbo chain saw that was given to me with no manual and i am new to useing them but always needed one .. now i got one ,... cant figure out how to mix the gas and oil... i allready bought a gallon of gas and 2cycle engine oil .. just need the ratios... i need help for both gas and oil... not sure how to mix the oil either.. sooo .. Please help...and also.. do i need a certain type of lubricant for the chain or can i just spray some wd40 on it