How much does water expand when heated, and does salt affect that? For this question, assume all things not mentioned are perfectly controlled, all at 14.7lbs of atmospheric pressure, and water is 100% pure of anything not mentioned, with no dissolved air.

Given a quantity of water that is 1 liter at 20°, what would the volume be when heated to 30°?

Secondly, the same question, except the water being heated is fully saturated with salt.
The volumetric expansion of a liquid is given by the following equation
$$\Delta V=V_0\beta\Delta T$$
where $\beta$ is the coefficient of thermal expansion and $\Delta T$ is the change in temperature.

Here's a link to a nice table containing coefficients of expansion for water, both pure and salinated.  Wikipedia shows the maximum solubility of salt in water to be around 36% (w/w).

From the first link we find that

for pure water at $25\ \mathrm{^\circ C}$: $\beta = 257\times10^{-6}/\mathrm K$

for water with 35% $\ce{NaCl}$ dissolved at $25\ \mathrm{^\circ C}$: $\beta= 297\times10^{-6}/\mathrm K$

Now you should be able to calculate the values you are interested in.