Just provide your scanned image or PDF (with images inside), select your language among 20+and desired output format and get within seconds your recognized text. From our tests, the service is very efficient providing you have at least a 200dpi source.
You can upload images and files up to 25Mo on the free version which is more than enough for casual users. Registered users will get more, while paid users will get more services, selection possibilities and options.
As always with all online services, be careful on the nature and confidentiality of documents you provide.