The datasheet speaks of a 'user-adjustable quiescent voltage'. The sensor output ranges above and below the quiescent voltage.
This means the sensor does not put out zero V with zero magnetic field. You won't get directly proportional output.
You must determine what is your useful range of sensor output. If you are measuring the degree to which the magnetic field is positive or negative, then you set quiescent voltage about halfway between V+ and ground. Output will range above and below that point.
Or else you can choose 10% of supply V, if you intend to measure only one polarity of magnetic field. This will allow you (for instance) to set a low level as OFF and a high level as ON.
The output may or may not be inside a suitable range to be used by your ADC. This is where you'll need to tailor-make a conditioning circuit. You may find it easiest to use an op amp. You'll be lucky if you find you only need a resistor or two.
Do you need proportional output (say for current measuring)? Then you must remove the DC component, before you feed it to the ADC.
Would need to "clamp" the amplifier to make sure it doesn't jump above, say, 3V in the case of spike in the magnetic field though.
This is a prime concern, to avoid damaging the next device.
You probably know how to arrange diodes or zener diodes to clamp the signal.
You'll need to observe what comes out of the hall-effect device, and also what comes from your conditioning amplifier, re:
(1) whether signal V goes below zero.
(2) whether signal goes outside the useful range of your ADC. You must make sure whether your ADC will be damaged in this case, and if so then prevent it.
(3) whether signal exceeds supply rails to your op amp, or from your op amp to your ADC.
Spec sheets for op amps, etc., often warn you must prevent any of 1, 2, or 3 occuring, lest a device be damaged.