With the wide variety of electric bass guitars on the market, the novice can be intimidated by such a dizzying array. There are so many different scale lengths, pickup configurations, neck profiles, and numbers of frets and strings available today; there needs to be a sensible and realistic starting point for starting bassists (especially younger ones).
The most logical first step is to keep the choice simple and inexpensive. A simple, classic four-string bass with one pickup is sufficient for any beginner (such as this Fender-made Squier Affinity Series Precision Bass) . Forget about multiple pickups and fancy tone controls; the focus of the beginner is to learn how to navigate and control the instrument. Likewise, forget about five, six, or seven string basses; the wide neck will only frustrate the novice's tender fingers and weak wrist, and the extended tonal range of these basses will only confuse them needlessly.
Be sure to buy one made by a reputable manufacturer as well. This does not mean that one must shell out thousands of dollars on a decent beginner's bass. Squier by Fender and Epiphone by Gibson are two example of excellent 'budget-lines' for beginners. Usually inexpensively mass-produced overseas or in Mexico, these instruments are built to meet the standards and specifications of their parent manufacturers in order to bear their names and reputations. Their drawback is that these student models aren't built for the demands of the road and stage, but are still sound great and are very playable (and often make great backup instruments for more experienced players).
Buying a decent used bass is also a good route to take. Music stores usually have great deals on gear that might have some scars and dings, but play and sound very nicely. Sometimes, even better deals can be found in your local pawn shops, or in the classified ads. Sometimes, however, unscrupulous types often use these methods to unload worthless junk upon unsuspecting beginners. In each case, it is advisable to ALWAYS ask around for references, or at least have an experienced bassist accompany the student when looking to purchase ANY used gear (remember: caveat emptor).
Finally, the best way to purchase a beginner's bass is to buy one of the many package deals offered by reputable manufacturers. These starter kits offered by companies like Epiphone and Sqiuer contain everything needed for a beginner to start playing immediately, including a small practice amp, cord, strap, and sometimes even 'short-cuts' to playing popular rock tunes. These packages are usually priced under $300.00, which is often much cheaper than buying all these pieces separately.