We have created a task and assign it to users. The user will get listings about the task. On click of task, how to navigate him to Task page which makes a reference to a question in a series of say about 400 question or more. How to send him to middle of a set of questions , can you suggest a good practice for achieving this?
I would take inspiration from codeAcademy.com
Basically, divide your screen up into a few sections, and use modal overlays to direct the user to specific tasks or steps.
Notice that on the top left of the Introduction to PHP it has a drop down of 1/13 That is used for navigation, and it is often broken up into groups. In your case, you might want to use the entire left space to allow the user to click into categories or sections, like a table of contents for a PDF.