Hokay, a quick primer on the levels command:
Go to Image -> Adjustments -> Levels, that brings up the big old levels dialog box.
The big graph in the middle is called a histogram and it shows you the brightness values in the image. This, incidentally, is the histogram of the raven banner image I gave you a link to. You can see we have almost no pure black, a lot of very dark greys, virtually no midtones, a lot of very light greys, and some pure white. You can just grab the little triangular handles and drag them around, it should be pretty obvious what they do. The one on the left sets the black point, that is to say as you pull it inwards it throws away those dark greys and replaces them with pure black. The right handle does the same thing, only for whites. Since we want a pure black raven on pure white background, just move the handles inward so that the two humps are on the outside.
Then get rid of the banner border, use a brush or the lasso tool or whatever you want, doesn't matter. Once you have just the raven hit ctrl+a to select the whole thing, ctrl+c to copy it to the clipboard, and ctrl+d to deselect again.
Next up, masks. A mask is a black and white image associated with a layer that determines the layer's transparency. Areas in the mask that are black are transparent, whites are opaque, and greys are translucent. You get a mask by selecting a layer and clicking the little "circle in a box" icon at the bottom of the layers palette.
Since we want a red raven (presumably), go ahead and create a new fill layer (Layers -> New Fill Layer -> Solid Color). It'll ask you for a name and then give you the color picker dialog box, so pick whichever color you want. Then select the new layer, make a layer mask and go to the channels palette. You'll see the RGB composite along with its components red, green, and blue, and at the bottom another channel called mask. Make sure it's selected
and visible (that's important) and ctrl+v to paste the raven into it. The only problem is that the raven is black, so now you have a red layer with a raven-shaped hole in it. Press ctrl+i to invert the mask while it's selected to remedy the problem, hide the mask channel and select the RGB composite again. And that's it.
The kicker is that now you can change the color of your raven simply by double-clicking the fill layer's thumbnail. That'll give you the color picker back and you can dial in a new color. Nifty, eh?