There are a couple of options.
1) Freelance websites
There are a couple of websites which offer various services for freelancers/clients, like offering an application to automatically keep track of hours worked and bill the client weekly for the previous weeks work. They also facilitate payment for fixed-price jobs and can do milestone payout. These websites usually have a fixed percentage that they charge of your income for their services. Odesk.com, elance.com guru.com, matchist.com and freelancer.com are all examples of this type of service. These websites also offer a platform for freelancers to post their service offerings and potential client to post jobs.
2) Escrow service
An escrow website could be used to facilitate the payment of milestones on a project. For example, escrow.com offers a service where the client pays them the money for the job, and when each milestone is completed successfully, they pay you.
3) Direct payment
The client could pay you directly into your bank account using a wire transfer. By agreeing to milestones, both you and your client could minimise the risk of with party failing to meet their obligations.
While these above do offer some degree of protection, there are other precautions you can take to minimise risk:
1) Ask for an initial payment percentage as a deposit before work begins and plan milestones for logical stages throughout the process.
2) Agree on definite criteria with the client for the milestones to ensure that the scope and criteria for completion of each stage is clear.
3) Initially start on smaller, less costly projects with the client before moving onto larger ones. This will allow you to establish a relationship with the client and build some trust with them