How to evaluate it

Read through the page and consider:

Publisher
Who is providing the information?
What do you know about the publisher?
Do they have a statement that explains their mission and goals?
What might their point of view be?

Is there a sponsor behind the author? If yes:
Is it clear what organization is sponsoring the site?
Is there a link to the sponsoring organization?
Check the domain (see how to evaluate authority)

Ask a reference librarian if information about the author/company/organization is available.

Purpose of the site
What goal does this site meet?
Why was the site written?
For whom was the site written?
How detailed is the information?

Advertising
Is the information free of advertising?
If there is any advertising on the site, is it clearly differentiated from the informational content?

Links
If there are any links to related sites, what kind of sites are they pointing to?

It is always important to know something about the background of the publisher of the web site to be able to estimate his/her/their point of view.

Always be aware that there will probably be some kind of bias.

Consider different sources to compare your results.