Postsecondary access and degree completion are increasingly important concerns for individuals and policymakers. This dissertation presents evidence on three distinct strategies for increasing students' level of preparedness for higher education, rates of postsecondary enrollment, and rates of postsecondary degree completion. The first is an intervention aimed at increasing eighth-grade students' familiarity with college life. Results from an experimental study indicate that students assigned to participate in campus visits demonstrate higher levels of knowledge about college, are more likely to have conversations with school personnel about college, put forth higher levels of effort while completing a college-related survey, and express a decreased desire to attend technical school. Additionally, treated students are more likely to enroll in advanced math and science/social science courses in ninth grade. The second strategy is a place-based program that guarantees a college scholarship to all students enrolled in the Promise district for ninth through 12th grades. Results from a quasi-experimental evaluation indicate that a Promise program in a rural area can increase postsecondary enrollment and bachelor's degree completion rates, although effects vary by student characteristics. For example, we find larger enrollment effects for students of color and for students with below-average grade point averages, but larger completion effects for white students and students with above-average grade point averages. The third strategy is on-campus support services, whose goal is to facilitate students' successful transition through college and to graduation. My descriptive analysis indicates that students' ability to access on-campus resources is correlated with their background characteristics and personality and may be hindered by faculty and staff's lack of awareness of available services. This work also indicates that students who utilize on-campus resources report higher levels of a sense of belonging and college persistence. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]