geminiluna:
thanks. I use a Canon 40D, and either 300L f/4 IS + 1.4x or 500L f/4.5 + non-reporting 1.4x (so it maintains AF) for birding photos, usually. (Both these lenses were bought used; the 500L is ancient - out of production for years). On a handful of shots in my galleries, I used my 70-200L (the downy let me get so close and the 70-200 is what was attached at that moment, for example). I use the 300 handheld, and a monopod for the 500.
I went to Africa in 2007 with just a Canon G7, so my oldest galleries - including a Zambia safari - were taken with just that point & shoot; I got the "bug" from that trip and got a DSLR and lenses since - which subsequently turned me into an amateur birder.
All these shots are taken outdoors (I've never tried to shoot through windows b/c of my yard setup, light angle, and glare and window distortion).
I've found it takes some patience and observation to figure out the best spots to capture images, taking into account light, poses, bird activity, backgrounds, etc - and then once in awhile, it's just plain luck. ;) But, with feeders in your backyard, it should be pretty easy over time to see different species' habits and get in position for better images, since you have multiple opportunities to observe and position yourself.
If you go to my galleries, any image that you open will have all exif data accessible - just hover over the top RH corner of the image and you'll see everything.
backyard bird gallery:
http://allenh.zenfolio.com/f448269862mostly avian wildlife gallery:
http://allenh.zenfolio.com/f557097489