Student loans used to be some of the easiest, and cheapest, forms of credit available. Not anymore.

The credit crisis has reduced access to student loans, thanks to a combination of defaulting lenders and tightened restrictions. Meanwhile, the cost of college tuition and fees continues to soar, rising at four times the rate of inflation since 1982, according to the National Center for Public Policy and Higher Education.

Here's what you need to know if you've got college bills to pay:

Federal versus private aid: Federal aid, which includes grants, loans and tax benefits, still represents the lion's share of funding for undergrads. Federal dollars accounted for 56% of aid in the 2007 to 2008 academic year, according to the College Board. Private sector loans represented 12%, an increase of 3% over the past decade. (The remaining 32% came from state and institutional sources.)

The rise in private funding is in part due to the relatively low limits on federal funding. Until last year, dependent undergrads were limited to a total of $23,000 in federal loans over their undergraduate careers. Although the limit was recently raised to $31,000, many borrowers must still turn to private loans to make up the difference.

The problem with private sector loans? They're not subject to the same rate caps and protections as federal loans. That means the average borrower pays interest at nearly double the federal rate of 6.8%. Furthermore, lenders have tightened their standards due to higher default risks. Lenders such as Wachovia (WB) - Get Report(WB) and Bank of America (BAC) - Get Report(BAC) have stopped offering private loans altogether. And lenders that do offer student loans, such as JPMorgan (JPM) - Get Report(JPM) and Citigroup (C) - Get Report(C), have tightened standards so that these loans are now out of reach of families without good credit.

(WB) - Get Report (BAC) - Get Report (JPM) - Get Report (C) - Get ReportFAFSA and more: As you pull together sources of college funding, it's important to ensure that you've maximized the amount of federal aid for which you are eligible. By filing the Free Application for Federal Student Aid, or FAFSA, online, you'll receive help from the system and the opportunity to chat with a live support agent. Most importantly, the paperwork will be processed more quickly, meaning you'll find out sooner, rather than later, how much federal aid you may receive or if you made a mistake that needs fixing.

Your college also may have its own set of financial aid forms and requirements. Many private institutions, for example, use the CSS Profile to calculate financial need. The CSS uses different criteria than FAFSA for determining which assets, such as home equity, are considered when setting aid packages. Errors in either the FAFSA or the CSS Profile can delay or reduce the amount of aid you qualify to receive. Consider consulting your financial adviser for help in filing the forms accurately.

(WB) - Get Report (BAC) - Get Report (JPM) - Get Report (C) - Get ReportScholarships and work study: Not all financial aid must be repaid. Institutions ranging from your college to the local chamber of commerce to organizations devoted to people from a certain ethnic background offer hundreds of thousands of scholarships each year. These range from a few thousand dollars a year up to full payment for tuition, room and board, and books. Search for scholarships via FastWeb Scholarship Search.

(WB) - Get Report (BAC) - Get Report (JPM) - Get Report (C) - Get ReportYou may also want to consider having your student contribute to the cost of his or her education by working on campus. The federal Work-Study program helps students pay for education costs by providing part-time employment opportunities at participating institutions. To apply, just check the appropriate box on the FAFSA form.