The important factors are align time and warp speed, but align time is the more important one. A ship's maximum warp speed affects how quickly it reaches that speed.
The fastest aligning and warping ship class are fleet interceptors (Ares, Stiletto, Raptor and Malediction) with a base warp speed of 8 AU and align times of a bit more than three seconds. If you transport cargo of any significant value I would recommend a Covert Ops ship (Anathema, Buzzard, Helios and Cheetah), which has an identical warp speed but higher align time of around 5 seconds. The Covert Ops cloak that those ships can fit makes it nearly impossible to get caught outside of 0.0 space in bubbles.
If you can't fly those, use an attack frigate (Slasher, Condor, Atron and Executioner). They have very low align times (<3 seconds), but a lower warp speed at 5 AU/s. But as T1 frigates they require almost no skills to fly.
The modules you want to use are Nanofiber Internal Structure II for better align times. Inertia stabilizers give a larger bonus, but also increase your signature radius. For better warp speed you want Hyperspatial Velocity Optimizer rigs.
I want to emphasize that if you transport valuable cargo, you have to follow the usual safety precautions and use undock and dock bookmarks to avoid being ganked. Someone will scan your ship and notice if you carry something valuable, and the ships I mentioned have nearly no tank at all.