Here's my recommendation (especially since the next 7-10 days will be mostly moonless):
Use whichever of your two telescopes you are most comfortable with - and the one that is easiest for you to find objects.
Use the 25mm plossl eyepiece with whatever scope you are using. It will provide the lowest magnification and widest field of any of those eyepieces.
Find M42. If you can see Orion's belt with your eyes, you can find M42 fairly close by (down just a bit from the belt). It is, at first glance, a hazy patch in the telescope. Within this hazy patch is a curved line of three bright stars and the four stars of the trapezium - very close together, forming a tiny trapezoid. You may have to look at them for a while to tell that they are four individual stars. Turn off every light you can control and look at the hazy patch for a while. It will start to get more detailed as you look at it. On the edges of your field of view will be many more stars. Try to take time to take it all in. It feels kind of like how I imagine looking out the window of a spaceship.
While you are in the area, go up to Orion's belt and slowly move your scope along the belt, looking at each of the three bright stars. In your 25mm plossl, you will find that this area of three bright stars actually contains dozens of stars. The stars on the left and right sides of the belt are doubles, with fainter companion stars right next to them. Again, the whole area gives a spaceship window effect.
Moving away from the eyepiece, look up at the sky, just with your eyes, and follow the line of the belt stars up and to the right. Following this line, you should spot the bright orange star, Aldebaran. Adding a little confusion to this, Mars will be a little higher up that Aldebaran, and look like an even brighter orange star. If you spot Mars first - look down a bit - you'll see Aldebaran. See if you can get it in your telescope (again, stick with the 25mm plossl).
Once you get Aldebaran in the scope, slowly pan to the right, and you'll see part of the Hyades, a bright open cluster - kinda cool, but not a great target in a telescope, and not your final destination.
Using just your eyes, look where your telescope is pointed. If it is around 7, 8, 9pm at night you will see the Pleaides a little ways straight to the right (not up or down) of where you are pointed. If you are using the dob (alt az) you may be able to just pan to the right from Aldebaran to find it. It won't quite fit in the 25mm plossl in the dob, but it will still look pretty great, and once you find it, you can't miss it - you will have about 30 stars, some of them very bright, in the eyepiece. (If the 5 inch reflector is f8 or faster, you can probably get all of the Pleiades in view with the 25mm plossl). Just counting the stars in the eyepiece will help you to notice the variety, and as you keep looking, you'll notice more stars.
This is the loosely guided tour that I took on the first two nights with my current telescope, making it up as I went along. It may take time to find these objects, even though they are brighter and easier than most DSOs. Keep at it. I didnt just point up at the sky and find them either. I used a 25mm Sirius plossl on this tour. With the exception of M42, everything you'll see is, when it comes down to it, just stars - tiny points of light. I think you may find them pretty amazing nonetheless.
Good luck and clear skies.
