Google-maps – link to Google Maps with the ‘LatLng Marker’ enabled

It's very straightforward. Just use the following link, changing the latitude and longitude for yours. The z is the zoom index, you can play with it to get where you want.

http://maps.google.com/?ie=UTF8&hq=&ll=35.028028,-106.536655&z=13

I got this information by clicking on the "Link" button in the right hand corner above a map. This will also allow you to get the latitude and longitude for a location.

I don't know of a good way to make a marker on Google Maps, through the UI anyway. Right click on a point and select "What's Here?" to create a marker, but it will be to the closest thing (business, intersection, address, etc). This essentially performs a search with the latitude and longitude and returns whatever is closest to your search. A URL to do that would be:

http://maps.google.com/maps?q=35.128061,-106.535561&ll=35.126517,-106.535131&z=17

With the q (for query I believe) being the coordinates where you want your marker.

A more effective method, if you are trying to send a link to a specific address would be to search for the address in Google Maps, which will give you a marker on the exact address and then use the "Link" button to get the URL for sharing.

BatchGeo is a good place to start. You'll need to look at their Spreadsheet Template to make sure that you're importing all the information you'll need. The Store Locator function is what you're looking for.