http://www.*****************.com/lightsimages/1.gif
first thing, what is the difference between NE555 and LM555 and the rest of the 555s?
Different manufactuters use different prefixes. Some are made to a different spec ie. Military, low power cmos. Get a copy of the 555 data sheet - available on the web.
1) on that diagram, where is the negative terminal of the battery?
Under the 0.01uF capacitor. That bit that looks like an upsidedown T is an earth/ground designator.
2) on the 100k preset resistor on the left, what is the line from the dot below it to the middle of it?
The resistance of a variable/preset is measured across the two outer pins. The centre pin is connected to a slider that allows you to vary the resistance between zero and maximum. To test it connect an ohmmeter across two of the pins and adjust the preset. If the value changes then one of the connections is on the slider.
3) what is the line all by itself at the very bottom?
This just shows an alternative arrangement for connecting the LED. Read te text that goes with the diagram.
i'm sure these are silly questions, but i'm just trying to make sure my timer works before i use it in a bigger project, so i thought this would be an easy way to test it
thanks
david