arg – Shift Tab again…
…anyway the weights can never go above 1.0 for any single vert group. You can set the values for several groups all to 1.0 but blender will always normalize them behind the scenes.
For example – 4 vert groups all set to 1.0 actually equals .25 each. (They will get a weighted average adding up to 1.0)
If you hit the button that says “normalize” it will adjust these values to display the ACTUAL normalized weights.
There are also 2 types of vert weights, deform and other. The deform groups are the verts will be effected by a bone, and the “other” are groups not intended for armature deformation.
I hope that makes sense – it is quite a bit to get your head around.