755 permission on public html folder

755,security

[NeilsPHP]

I have been reading a lot and after some research,I am only more confused as to which way I go.I am trying to find a way so that:
1.my site can interact with users by letting them upload pictures
2.site is safe from hackers

but for me to do 1st,i have to leave public_html at 755 or my php script won't work.my question:
1.can i use ftp to do this ? what is the best way
2.best solution for shared server ?

any links or scripts/snippets would be appreciated.

p.s.i seem to trust this portal now more than anybody else on web..gr8 job from moderators.
thanks

[cameraman]

755 a subdirectory and upload the files to it instead of your public_html.