#1
Alright, so I'll be starting a pedal board soon.

What are the best positions for certain pedals... I see that the placement of them affects your sound?

So, like, what goes first? OD? Delay?

I just want my tone to be decent, and if the position of pedals causes problems, like hum or unwanted noise, I'd like to try and eliminate that before it occurs.

Maybe give me examples of what's worked (or works) for you, causing the least interference.
#2
Use time and sound modulations (reverb, delay, chorus, flanger, phaser, etc.), EQ's and other on/off effects in the loop. Use an OD, Noise-Gate, Wah's, and other things meant to change the tone/adjustable (wah, whammy) pedals in front of the amp.
My set-up right now goes: Guitar->TS7-Boss GE-7 (EQ, low level to get effect and no noise) -> Boss NS-2 -> 6505 and my Zoom G7.1ut in the loop which adds in chorus, delay, and acoustic simulator in the loop for the clean channel, and then has a pre-set which is just a volume-boost/volume pedal in the loop (really cool sweep effect when this particular volume pedal is in the loop).
EQ's and Volume pedals can either go before the amp, or in the loop for preferance. I like to have my EQ on all the time, so I have it in front of my amp after my OD, with the level turned down low to get the effect of the EQ, and no noise after with the NS-2. This is decent, considering a lot of people say the NS-2 sucks tone, but in my particular set-up, it doesn't, so I'm happy with where it's at right now. The most I'd change is the effects in the loop down the line.
#4
Mess around with the EQ and Noise gate positions. Some like them in the loop, some like them before the amp.

Some modulations actually may sound better in front. My DejaVibe, in particular, sounds really too much like a phaser when in the loop, but when in front of the amp, it sounds much more amazing.