This will work:

<!-- language: python -->

    layer = iface.activeLayer()

    features = layer.selectedFeatures()

    for f in features:
        print f.attributeMap()

In PyQGIS 3:

<!-- language: python -->

    layer = iface.activeLayer()

    features = layer.selectedFeatures()

    for f in features:
        # refer to all attributes
        print (f.attributes()) # results in [3, 'Group 1', 4.6]

    for f in features:
        # refer to a specific values of a field index
        print(f.attribute(1)) # results in Group 1