I can explain electrostatic induction.
Before I begin, remember that like charges repel (+ repels +, - repels -) and opposite charges attract (+ attracts -, vice versa).
Let's imagine that you have three metal bars (A, B and C)
Metal bar A is positively charged (more protons (+) than electrons (-))
Metal bar B and C have no charge (in other words, there are equal amounts of protons (+) and electrons (-))
Put the two bars (A and B) side to side like so: Bar A__Bar B (__ = two sides are near each other, but not touching)
Since A is positively charged, and it has more protons than electrons, electrons will be attracted to bar A. Therefore, electrons will accumulate on the left side of bar B (the side closer to bar A), creating a slight negative charge in the left side of bar B, which then creates a slight positive charge on the right side of bar B (the side away from bar A).
Diagram: ++BarA++ + Bar B = ++BarA++_-- Bar B ++
If you were to take away Bar A completely, then Bar B would return to a neutral charge. Why? Without the positive charge of Bar A, the electrons will no longer migrate to the left side, and the electrons will be dispersed evenly throughout bar B causing the entire bar to be neutrally charged.
Diagram: ++BarA++_-- BarB ++ - ++BarA++ = BarB
However, let's assume you take a third metal bar (Bar C) and place it next to the right side of Bar B (in this case, however, Bar B and Bar C do have contact.)
Diagram: ++BarA++_-- BarB++--BarC++
Remember that the right side of Bar B has a slightly positive charge because the electrons migrated from the right side to the left side. The slightly positive charge on the right side of Bar B will then create a slightly negative charge on the left side of bar C (the side nearest to bar B) the same way that Bar A created a negative charge on the left side of bar B (the side nearest bar A). However, since Bar B and Bar C actually touch, electrons from the negative side of bar c (closest to bar b) are transferred to Bar B [Note: Charge is always transferred by electrons. Since electrons orbit the nucleus, they can be transferred much easier than protons.} This means that Bar B gains electrons (thus gains a negative charge) and BarC loses electrons (thus gains a positive charge) even if you take away Bar A.
Diagram: BarB++--BarC.....--BarB-- _++BarC++
Another example can be found here:
http://en.wikipedia.org/wiki/Electrostatic_induction
Anyway, I tried to explain it as thoroughly as possible, but physics is hard to explain over the internet.
Hope it helps,
-Dr. P.