It is very important to provide hints to the visitors to your website at all possible places in order to make it easy for them to work. This requires a lot of time and effort on the part of the designer.

Visitors Don't Know Your Site
Most of the visitors will not be familiar with your site. Some of them might be coming back again. However, the web is not anymore dependent on the search engines and links from other sites. Due to this, it is required to add hints wherever possible. Hints should appear automatically whenever there is something that looks mysterious or the user wants to know something.

Question Mark Icons
The best way to perform this task is to put question mark icons with confusing things. For e.g:

Register for Online Billing
Name: ____(?)
Address: ____(?)
Account no.: ____ (?)

These question marks have been provided because most people would not remember their account number by heart. When this question mark is clicked, an image of the bill will be displayed which will point to the place where the account number is mentioned.

Alt Text
Alt text stands for the text that is put within the image tag's alt property. It is the content to the image Alt's tag.

<img src="image.jpg" alt="alt text here" />

This text is used to provide an alternative for the browsers that do not display images. Another use of it is to provide hints. This is called 'tooltips'. For example, to give a tool tip to a printer icon, that opens by a click of the mouse, then print CSS and then print, the following tags is written:

<img src="print.jpg" alt="print this article" />

Whenever the users are uncertain with respect to the printer icon, a tool tip will appear that will contain  the text “print this article”. This is used to tell the user what will happen on clicking a particular link.

Javascript
Javascript is used to make the hints context-sensitive. It is used to make it look attractive, as well as to  automatically display the hints. For instance, in a form asking visitors to enter their state and date of birth.

Javascript's on focus event can be used to write a code that will highlight the box in which the user is typing as well as to provide a hint to him with it.

This approach is required to provide hints whenever required. You can make your site useful by making it sensitive to the context to help the users to get things done.