Understanding Transistors
There are many errors in the diagrams. How you connect these transistor, is called Common Emitter, and is one of the three ways in which you can connect a transistor.

For common emitter configuration, it is usually considered that the load is connected in the collector circuit. To light a led, the basic circuit would be:







simulate this circuit &ndash; Schematic created using CircuitLab

When the source \$V_b\$ is applied, the LED ligths on.

The LED is connected in the output circuit. The LKV for this:

$$
V_{CC} = I_C\,R_C + V_{D1} + V_{CEsat}
$$

For example, if \$V_{D1} = 1.2\,\mathrm{V}\$ (like common red LED), \$V_{CEsat}= 0.8\,\mathrm{V}\$ (Collector-emmiter saturation voltage) and \$V_{CC}=9\,\mathrm{V}\$

$$
I_C\,R_C = 7\,\mathrm{V}
$$

for a common red LED, we can suppose 15 mA, then

$$
R_C = \dfrac{7\,\mathrm{V}}{15\,\mathrm{mA}} = 466.66\,\Omega\approx 470\,\Omega
$$

The input circuit is on the base terminal. For a current collector of 15 mA and a factor \$h_{FE}=100\$ (typical)

$$
I_B = \dfrac{I_C}{h_{FE}} = \dfrac{15\,\mathrm{mA}}{100} = 150\,\mu\mathrm{A}
$$

If \$V_b = 3.3\,\mathrm{V}\$ (typical for a \$\mu\$C) and \$V_{BE}=0.7\,\mathrm{V}\$ (Base-emmiter voltage for a silicon transistor, typical)

$$
R_{b} = \dfrac{V_b - V_{BE}}{I_B} = \dfrac{3.3 - 0.7}{150\times 10^{-6}} = 17.333\,k\Omega\approx 18\,k\Omega
$$