Purchasing your first rental properties and establishing yourself a credible investor to the banks is often one of the most difficult struggles that I've heard a lot of new investors face. The properties should ideally pay for themselves + cash flow, but often banks will want to see two years of stabilized rent for a new landlord/investor before they can consider this rental income towards future loans. If you have good credit and tax returns that can justify the loans now, they may be able to offset this lack of experience, buying you time to use the properties as income for future loans. If not, however, there are some pretty good private/hard money programs out there that may be able to get you started and build your reputation as an investor.
These loans will be more expensive, but this lowers your margins and can force you to find better deals as well.
If you have any questions, feel free to ask.
Andrew Bowlds, Private/Hard Money Consultant