Step 1: Understand the physical concept.
Work done in assembling charge on a spherical shell is equal to the electrostatic potential energy stored in the system. Step 2: Potential on a spherical shell.
For a conducting spherical shell:
\[
V = \frac{1}{4\pi \varepsilon_0}\frac{Q}{R}
\] Step 3: Work done expression.
Work required to assemble charge:
\[
W = \frac{1}{2} QV
\] Step 4: Substitute value of potential.
\[
W = \frac{1}{2} Q \cdot \frac{1}{4\pi \varepsilon_0}\frac{Q}{R}
\] Step 5: Simplify expression.
\[
W = \frac{Q^2}{8\pi \varepsilon_0 R}
\] Step 6: Final conclusion.
Thus, the work done is:
\[
\boxed{\frac{Q^2}{8\pi \varepsilon_0 R}}
\]