I want to start trading in Bitcoin to dollar,
but I looking for someone sends me mesages
every day tells me it's time to buy and it's time to sell.
Where can I find this person? 
Their is no one who can give you correct details about when to buy and sell , it is always that first you go through with small traders and get experience of what is happening and then trade according to your mind or heart says. If you can any professional service then just go for it