Most law schools will require two letters of recommendation and many show a strong preference for academic references for applicants, unless you are more than five years out of college. Many may indeed accept up to four letters of recommendation, but keep in mind that more letters is not always better. Since the preferred number and type of letters of recommendation to submit will vary from applicant to applicant, if you are unsure, please feel free to discuss this with your pre-law advisor.
In requesting a letter of recommendation, your goal should be to contact someone who knows you over a period of time and thinks well of your work. Try to reach out to professors and supervisors who have seen you in either academic or professional contexts and can readily compare your work with that of other students, including previous and current Penn applicants. Settings in which your writing, communication, research, and analytical skills are being utilized and observed are usually best. This person should be both willing and able to take the time to write a thoughtful and thorough evaluation. If the recommender is well-known in his or her field, this can be an added plus, but only if the other factors are there. In other words, it is preferable to have a strong, detailed letter of recommendation from someone who knows you well than a few lines from a famous professor who can say very little about you specifically.
When asking for letters of recommendation, it is important to get a genuine sense whether he or she is indeed willing to write for you. Your request should be phrased in such a way that, if the potential recommender does not feel comfortable writing for you, he or she can gracefully decline. Pressuring someone to write a letter for you is likely to result either in a lukewarm or qualified recommendation, which ultimately may do more harm than good. A tactful question, for example, might be, "Do you feel you know me well enough to write a strong letter of recommendation supporting my applications to law school?" With that in mind, you should aim to make this request in person if possible; if not, then a phone call is appropriate. Only if no other way is feasible should you ask someone by email to write you a letter of recommendation.
Once he or she agrees to write a letter of recommendation on your behalf, it can be helpful to discuss your academic interests and your career plans with your recommender. Letters are most effective when the writer can describe you as being well-suited to a particular goal. Remember that career goals are a work in progress and that you can easily discuss your general interests, as well as specific plans, depending on your situation. Your recommender will also be curious about your backgound. To that end, providing an updated resume, current transcript, and any other relevant information is usually very helpful.
Once your recommender agrees to write on your behalf, it is always useful to mention your timeframe and, if necessary, a general deadline by which you would like this letter submitted. Giving a recommender at least 3-4 weeks to write a letter on your behalf is a good rule of thumb. Be sure to be as flexible as possible, while still maintaining a realistic sense of when this task must be completed. After the initial request has been made, you should feel free to follow up appropriately, but not excessively.
Sending Letters of Recommendation
Since most law schools give more credibility to confidential recommendations, we strongly suggest that you indeed waive your right to view your letters of recommendation.
All law schools will accept letters of recommendation from the LSAC's Letter of Recommendation (LOR) Service. If your letters of recommendation are being sent directly to LSAC, please make sure to provide your recommender with the corresponding LOR Form and a stamped envelope addressed to LSAC to expedite this process. It is your responsibility to keep track of the status of your letters of recommendation.
Interfolio is another option for storing and ultimately sending letters of recommendation. Once letters of recommendation arrive there, you may request that Interfolio send them directly to LSAC along with the corresponding LOR Form.
Once your letters of recommendation arrive at LSAC, you will be asked to direct your letters on file to individual law schools through the LOR Service; you will make that determination based on each law school's required number of letters, or the applicant's desire to target certain letters to certain law schools. It is not at all necessary to have targeted letters of recommendation for specific law schools, though if it's appropriate in your situation, then it is certainly an option.