Whenever you want to return to this web site, again click on Bookmarks and then click on the name of the site on the pulldown menu. When you want to return to that site, again click on Favorites and then the name of the site in the pulldown menu. Don't download anything from an unknown source. Virus protection software is worth having, should be updated, but can't protect you from everything. If you are downloading from a major public source like Netscape or RealNetworks or Microsoft , I wouldn't worry about it.
Computer viruses are much like real viruses.
You can easily catch them from people who have no intention of giving them to you. Create named folders for all your work and downloads by entering windows explorer clicking on dive C, choosing a location for the folder and right clicking on the right hand side of the screen and creating a new folder and naming it. If you download anything, be sure to remember where you put it. Write down where you put it and what you put there. If you hate to write on paper - like me, its a good idea to place all downloads in a subfolder within a folder ideally named downloads.