I talk my friends through this all the time! If you have more than one person you don't want seeing certain things on your page, set up a group for them.
Click on Friends, then All Friends (at top of page).
On the left-hand side, it says Lists. Click on +Create to make a list and name it whatever you want.
Now just click on the friends you want on this list.
Now to hide things from that group, click on Settings, then Privacy Settings (at top of page)
Go through the different sections and do this for everything you don't want that group seeing:
Profile: Click on one of the drop down lists where it says Networks and Friends.
Click on Customize
When the box pops up, it'll say Except These People - now type in the name of that group.
Do that for your wall posts, comments, friends, things like that. Now that group won't see these things you've hidden from them.
You can also use this group to look like you are offline all the time on chat.
Hope this helps!