Questions about colorizing pictures

It seems like I may have seen some on here along time ago.  I am just not sure.  

Anyway, have any of you done it?  I want to do it desperately.  Whenever I see some older photos of historical figures, I love the way it looks (when it is done well).  I like to think it humanizes a person.  It makes them more "real".

Well, in case anyone is wondering     , that is my great-grandmother in the avatar.  I just think she looks so cute in the picture.       Anyway, I have a few photos of family members that I'd like to colorize.  Whenever I look up on how to do it, I can only find links about photoshop.  I have never used it.  I don't really want to spend money on something that I am not going to use for a long period of time.  At least I don't want to spend a lot of money on something like that.

Does anyone have any suggestions about this?  If you think photoshop is the best, no matter what, OK.  But I really want to give colorizing family photos a try.  Just for the fun of it, if nothing else.    

Thanks.  I thought she was the one whose colorized pictures were the ones I saw on here, but I wasn't 100% positive.