what can i put into my fish tank??

[SC Fish]

if i went to a forest or lake and found a piece of drift wood or a nice looking stone (for an example),

can i go home , boil it (to remove viruses and whatnot) and just add it to my tank? 

what are the procedures to do something like this? 

[Adam Swarbrick]

Generally deciduous hardwoods are okay like oak but you should be wary of evergreen branches as they will leach sap into the water column.

 Most rocks are pretty safe to use in tanks, I do it all the time, just boil them up as you have said to kill any bugs that are on there.