I want to go somewhere and i want to download the whole route with direction as pdf . Is it possible
Your best bet would be to use a PDF printer like CutePDF Writer (free). It installs as a printer on your Windows computer, and then you can print the directions in Google Maps straight to the CutePDF printer, which will let you save the file as a PDF.
If you're using OSX, just select PDF from the print dialog and you can save a PDF to your computer.
For saving webpages for later reading, I use the ScrapBook Firefox plugin.
You might also give this wed site a go at it: http://www.web2pdfconvert.com/Default.aspx