When it comes to 2D games you will find the biggest chore will be the tile sets you use. I dont suggest you use the RPG xna builder thing that was suggested for the reason that it implements scripting, which is hard to understand and takes away from understanding exactly whats going on under the hood. The hardest part about building an attractive and fun 2d game is the art assets. Quite literally you will spend 90 percent of your time doing the art if you dont have artists helping you out. Which sprites are a pain in the ass in my experience. If you want to get a good foot in the door on tile maps. xnaresources.com and riemers.net have really good tutorials regarding xna in general. Although riemers is a bit intimidating for a newcomer in programming. Ummmm some books i would recommend for 2d games would be XNA 4.0 Game development by example which is the author hosts xnaresources.com. Reading the few xna books out there will really help you get a grasp of xna and game development in general. Also if your still new to C# going through the tutorials on Csharp-station.com would be highly recommended.