How to solve noise,echo, distribution of sound over speakers

[angelita]

hi i need some help

would u give me Topics for what i am looking for and
want to know how to begin and where to search

my project which is about

distributing the human( live voice ) over several speakers in an open location which contains trees ,buildings ans so..
(((its like building a sound system for school as an example)))


so please what ur reccomendation about that
i want names of subjects so i can solve these problems:

my problems are :
where can i put these speakers ..how i know what is the best location and orientation for these in order to get the perfect sound from all speakers and without echo
how the sound will affected by the dimension of the building
of course there is an equation for these.. right

if u suggest some software hardware that will help ...

and again i just need to know where to go and search ..nothing else

 

[ranger]

This should give you a decent start:
http://tinyurl.com/ykglfp9