I would like to find good detailed tutorials on how to use the following programs or programs that would do these things:

NifScope
Blender

or programs that let me edit meshes

Blender's website should have a goodly number of tutorials for the beginner and experienced modeler alike... but as for NifScope, well, I never did manage to find any. Instead I wound up playing around with it myself.

Is there anything in particular you're trying to learn how to do?

well I was trying to make a custom weapon and I am seeing that i need to use one of those programs but not sure how to edit them

for nifskope- look at the CSWIKI for overviews of the contents of nifs and how to generally manipulate the data, .

any of the dozens of tutorials dealing with specific types nif editing tasks, will help a lot of demystifying nifskope, for example i have writen a tutorial on how to create setup material controllers solely within nifskope. < doing that you will understand how to setup several other types of animations as well, alpha controllers, texture transforms etc

nifskope doesn't really need a tutorial how to use it. you just either rclick or lclick, and type things in to the various parameters.

For Blender I recommend the Blender - Noob To Pro tutorials collection.

Check the link in my sig. Antistar and I put together a comprehensive Blender / GIMP tutorial that has both a Video and a Documented/Process versions.

There are some newer features, but that will get you started with the basics. When you export your models now however, make sure to select the "Export as bsFadeNode" so that you can load it right into the GECK without having to go through the NifSkope step.

Luck,

Miax