Geoprocessing guidance for African water project

ThomasJackson

A newbie (me) would love some geoprocessing, model building guidance.  Conceptual advice is appreciated.  I also have 2 specific questions: a) What tools are best to create my outputs?  2) Do I need to pre-process the layers since they are in different formats (polygons, xy data, etc.)?  Many many thanks!

Outputs
1) Show polygon areas on African map when ALL of the following criteria are met
�?� Water depth = �??Shallow�?�
�?� Population density = between x and y people per km
�?� Land usage = �??Rainfed mixed crops�?� or �??rainfed corn�?� or �?� (I will select 20 out of 73 categories)

2) # of people that live in those polygon areas, broken out by country

MY MAP LAYERS

WATER DEPTH
This shows water depth categories at various points in Africa (shallow, very shallow, etc.).  I started with an XY table and converted it into a shape file.  Info from Properties:

Data Type:  Shapefile Feature Class 
Shapefile:  C:\Users\T. Hardy Jackson\Documents\Consulting\KickStart\GIS\KickStartGIS\WaterDepth.shp
Geometry Type:  Point
Coordinates have Z values: No 
Coordinates have measures: No 
Geographic Coordinate System: GCS_WGS_1984
Datum:   D_WGS_1984
Prime Meridian:  Greenwich
Angular Unit:   Degree

POPULATION DENSITY
This shows population density at particular points (500 people / km at long xyz.xyz and lat xyz.xyz, etc.)

Columns and Rows:  2160, 1920
Number of Bands:  1
Cell Size (x,y):  0.0416666667, 0.0416666667,
Format:   BIL
Source Type:  Generic
Pixel Type:  Unsigned integer
Pixel Depth:  32 Bit
NoData Value:  
Pyramids:  level: 3, resampling, Nearest Neighbor
Spatial Reference: Undefined

LAND USAGE
Shows how land is being used at various areas in Africa (73 categories)

Columns and Rows:  40322, 19446
Number of Bands:  1
Cell Size (x,y):  0.089281971, 0.089281971
Format:   GRID
Source Type:  Generic
Pixel Type:  Unsigned integer
Pixel Depth:  8 Bit
NoData Value:  255
Pyramids:  level: 7, resampling, Nearest Neighbor

Spatial Reference: GCS_WGS_1984
Angular Unit  Degree (0.01745�?�..)
Datum:   D_WGS_1984

AFRICA COUNTRY MAP
Shows country borders.

Data Type: Feature Service Feature Class 
Location: http://services.arcgis.com/MdapRpkzb0PVHqL1/arcgis/rest/services/Africa_Noll/FeatureServer
Feature Class: 1
Feature Type: Simple
Geometry Type: Polygon
Coordinates have Z values: No 
Coordinates have measures: No 
Geographic Coordinate System: GCS_WGS_1984
Datum:  D_WGS_1984
Prime Meridian: Greenwich
Angular Unit:  Degree

ThomasJackson

Help!  Please!!