ISO/Aperature Advice

[bartmaverick]

Hello,
I just purchased a Canon EOS Rebel Xsi and two lenses (29-135mm IS USM and 70-200mmL IS Zoom).
I am a beginner so I just went out to photograph some ducks (attempting to get in flight pictures using the 70-200mm). I just put it on the auto mode and was really quite amazed at how fast this worked and the quality of the pictures that came out. With that said I would like to be able to sharpen my skills and that of my photos.

If anyone has some advice for a beginner on how ISO/Aperature work together I would love to hear it. I am mostly focusing my photography efforts on wildlife and landscape which means I will find myself in lower light conditions although not exclusivley.

Thanks

[big baldo]

Theres a sticky at the top of the page that explains alot. Its called "the four basics". All of the stickys in these forums are loaded full of great info. Good luck!!