Hi PV Subramanian,
All the information you need are stored with the properties of corresponding API objects. You just need to iterate the components of the assembly to get properties of component. In each component, iterate its native document (say part), iterate features collection and get properties. The code snippet is a kind of skeleton for your reference.
However, if you not familiar with objects, assembly structure, part structure, I strongly recommend you take a look at the training labs, either video, or PPT:
https://github.com/ADN-DevTech/Inventor-Training-Material
http://adndevblog.typepad.com/manufacturing/2013/05/api-webcast-archive.html
Dim oTopAssembly As AssemblyDocument = m_inventorApp.ActiveDocument
Dim oEachComp As ComponentOccurrence
For Each oEachComp In oTopAssembly.ComponentDefinition.Occurrences
'transformation of component w.r.t to the global coordinate system (in context of top assembly)
Dim oTrans As Matrix = oEachComp.Transformation
'for other properties of component, please check API help. e.g. component name
Dim oCompName As String = oEachComp.Name
'*************
'native document of this component
Dim oNativeDoc As Document = oEachComp.Definition.Documen
'to check part document
If oNativeDoc.DocumentType = DocumentTypeEnum.kPartDocumentObject Then
Dim oNativeDocDef As PartComponentDefinition = oNativeDoc.ComponentDefinition
Dim oEachFeature As PartFeature
For Each oEachFeature In oNativeDocDef.Features
Dim oExtrudeF As ExtrudeFeature = oEachFeature
'check feature's type. e.g. whether it is an extrude feature
If oEachFeature.Type = ObjectTypeEnum.kExtrudeFeatureObject Then
End If
'get faces collection of the feature
Dim oFaces As Faces = oEachFeature.Faces
Dim oEachF As Face
For Each oEachF In oFaces
' iterate each face. get properties of face. or edges of the face...
'please check API help.
Next
'get definition of the feature
Dim oExtrudeDef As ExtrudeDefinition = oExtrudeF.Definition
'get sketch with the feature
Dim oSketch As PlanarSketch = oExtrudeDef.Profile.Parent
'dump information of sketch
Dim oGeoCons As GeometricConstraint
For Each oGeoCons In oSketch.GeometricConstraints
'each geometric constraint
Next
Dim oDimCons As DimensionConstraint
For Each oDimCons In oSketch.DimensionConstraints
'each dimension constraint
Next
Next
End If
Next