I've only hunted turkeys in Northern California, and the following is based on my personal experience:
For spring hunting, the best time to go is early in the morning. From personal observation, turkeys are pretty consistent in their morning patterns, so if you've previously seen them in a certain area during morning hours, I'd head to that same spot. Set up a few hen decoys near the spot you want to sit. Bring a call with you (you can get a mouth call, slate call, or box call). If you aren't experienced with mouth calling, I'd go for a box call. Find somewhere near where you can semi-comfortably sit still at for least a few hours. I like to cut some brush and put it in front of where I sit, that way if my leg falls asleep, I can move it without it being too obvious. They also can't see me move my box call that way either.
When it starts getting a little light, you'll want to throw out a few calls and see if you get a response. If you hear some responding to you, keep calling back until they migrate your way and see your decoys. Don't overdo it on the calling, you want to sound like a real turkey. Call, then wait for them to respond, then call again. If you are talking to them and there is a long period of silence, throw out a few more calls in case they got a little lost trying to find you. If you are in a forested or brushy area, wait until the whole group appears because a lot of times the bigger guys will hang out in the back. Stay as still as possible when they are approaching (when you hear them getting close, I'd get your gun in position so you don't wave it around in front of them when they appear). My Dad says turkeys can see the whites of your eyes move. I think he is full of **** but I still stare straight ahead (where my decoys are) when they come into sight, just in case he is right.
Don't get too excited and take a shot before they are close, because once you shoot, they are all going to fly, so make it a good shot. They will usually come all the way up to your decoy(s) and check things out (and sometimes try to mate with it lol, but that's usually just the Jakes, because they're amateurs
). Just be patient. When you take a shot, aim for their neck or head. Don't shoot them in the body or you're not going to have a fun time eating it. If you miss, they will fly for a short distance then re-group, so if that happens, just try to follow them as best as you can while they are flying and you may have another shot. If you break them up and they don't immediately re-group because they can't find there buddies, this is a great time to call because they will be listening in for other turkeys' locations so they can re-flock (is that a word?).
After you shoot one (assuming you do), if it is still flopping around, you'll want to step on it's neck with one foot and stop on it's neck with the other (I hate this part, just don't look it in the eye while you do this). Almost all the usable meat on a wild turkey is on the breast, so I just breast them out. Always brine wild turkey before you cook it or you probably aren't going to like it. Check the laws in Oregon before trying this tip, but if you find out where they roost, another good spot would be to set up close to there, since when they drop down in the morning, they don't usually fly very far from the tree.
This advice might be too late for you, but I thought I'd post it in case anyone else wanted some pointers. By the way, if anyone gets one, if you could keep the feathers, or just bring the breasted out turkey to me, I have a friend that makes earrings with the feathers and the owner of Cowgirl Cash likes to use them for gift-wrapping, and since she donated to our banquet, I'd like to find her some feathers to bring her
. I won't pay for them, but I will help you out on a project or something the next time you need help. My Mom and her Husband already limited out, but they forgot to keep the feathers for me.
As for where to go, I heard John Day was good. Other than that I don't know too many areas yet. I should have probably been out scouting weeks ago, but I figured I'd have been back to CA by now for a visit and hunt, and I know where the turkeys are down there.
Other tips:
Don't drink too much coffee beforehand, otherwise you'll have to get up and pee.
Make sure your lower back is covered all the way by your shirt/jacket (this is probably more of a female clothing problem). If it's not, brush, grass, or insects could touch you and either annoy the hell out of you or make you itch.
Bring throat lozenges in case you get a dry/sore throat, so you are less likely to cough.
Dress warm in lots of layers, because you are going to be sitting still for awhile.
Don't get poison oak.
Kelly