One thing that i am big on believing is to believe nothing until proven to you, obviously this wont apply to everything eg.
Friend 1: hey Jeff i saw a dog swimming in the river today (figured if i said "friend 1" would seem like i have more then 1 friend)
Me: have you got analytical data to support you statement? >:(
nononon i mean with more serious statements
obviously trivial things dont need to be questioned. I find after going through school, people are getting raised to learn what the teachers tell them, there is no real proof or reasoning behind anything, its just X is true, which is not a very logical stance to take.
Now i have had this argument many a time and it is mainly about religion i guess so i will use that in this example here, now i hold nothing against religious views and if someone worships zues then i will respect that, thats cool. But if someone was to expect me to believe it because of some case it would not be wise to just accept the claims without first questioning the 'authority', why should i believe it? And no because 100 years ago a group of people saw the sun dance does not count. First of all a third person source is normally very unreliable as you never know what someone has missed or edited out of the evidence, another thing people try to say is that because something cannot be explained it is therefore explained (eg. i saw the tv turn on by itself therefore its a supernatural power) all this really tells you is you dont know why the tv turned on itself

Anyway this leads back to the point of questioning authority, now this means if someone or come corporation tells you something without really supporting their statement with evidence its ok to say, why should i believe that, and ask for further evidence and this is something i feel is being neglected to be taught in schools and anywhere else really, children should be encouraged to question authority as they are growing up. It encourages creative thinking, open mindedness (willingness to believe statements that are not what you believe given the evidence presented is sufficient) , critical thinking, and better understanding of their true beliefs (wont believe things because the man in the straw house told me its true)
Obviously its impractical to question everything but its good to question somethings at least a little especially in this world full of liars, crazy people and con men. it would be great if all truth statements presented to us were always true but thats not the case. So yep, thats what i think. I encourage questioning everyone and everything :D