Buying a second home isn't that much different from buying a first home. Affording it usually depends on your ability to qualify for a mortgage on the second home. Benefits include tax breaks, a getaway for the family on vacations or holidays, a future retirement home, renters making your mortgage payments for you, or just a smart investment.
Many people see buying a second home as an investment opportunity. You'll need to identify sources for your down payment, since you're not selling your current house and using the proceeds, and you'll need to expect a larger monthly obligation for housing expenses.
Keep in mind that if you declare it as a rental, your mortgage might be slightly higher. Work with your lender to create a customized loan program with the best combination of rate, points, and closing costs for your needs.