Need Help Modding Server

I'm fairly new to running servers. but i'm using the newest forge server. everytime i install a compatible 1.6.2 mod i get a crash. same thing happened with me on 1.6.1. I just install it to the mod folder in the server. Like i said i'm new so go easy on me but any help would be much appreciated. i'm running windows if that helps at all. here is my full log:

[iNFO] Starting minecraft server version 1.6.2

[sEVERE] Encountered an unexpected exception NoClassDefFoundError

java.lang.NoClassDefFoundError: net/minecraft/client/renderer/EntityRenderer

at java.lang.Class.forName0(Native Method)

at java.lang.Class.forName(Unknown Source)

at cpw.mods.fml.common.ModClassLoader.loadBaseModClass(ModClassLoader.java:101)

at cpw.mods.fml.common.modloader.ModLoaderModContainer.constructMod(ModLoaderModContainer.java:483)

at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)

at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)

at java.lang.reflect.Method.invoke(Unknown Source)

at com.google.common.eventbus.EventHandler.handleEvent(EventHandler.java:74)

at com.google.common.eventbus.SynchronizedEventHandler.handleEvent(SynchronizedEventHandler.java:45)

at com.google.common.eventbus.EventBus.dispatch(EventBus.java:313)

at com.google.common.eventbus.EventBus.dispatchQueuedEvents(EventBus.java:296)

at com.google.common.eventbus.EventBus.post(EventBus.java:267)

at cpw.mods.fml.common.LoadController.sendEventToModContainer(LoadController.java:193)

at cpw.mods.fml.common.LoadController.propogateStateMessage(LoadController.java:173)

at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)

at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)

at java.lang.reflect.Method.invoke(Unknown Source)

at com.google.common.eventbus.EventHandler.handleEvent(EventHandler.java:74)

at com.google.common.eventbus.SynchronizedEventHandler.handleEvent(SynchronizedEventHandler.java:45)

at com.google.common.eventbus.EventBus.dispatch(EventBus.java:313)

at com.google.common.eventbus.EventBus.dispatchQueuedEvents(EventBus.java:296)

at com.google.common.eventbus.EventBus.post(EventBus.java:267)

at cpw.mods.fml.common.LoadController.distributeStateMessage(LoadController.java:104)

at cpw.mods.fml.common.Loader.loadMods(Loader.java:510)

at cpw.mods.fml.server.FMLServerHandler.beginServerLoading(FMLServerHandler.java:86)

at cpw.mods.fml.common.FMLCommonHandler.onServerStart(FMLCommonHandler.java:350)

at net.minecraft.server.dedicated.DedicatedServer.func_71197_b(DedicatedServer.java:69)

at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:443)

at net.minecraft.server.ThreadMinecraftServer.run(SourceFile:582)

Caused by: java.lang.ClassNotFoundException: net.minecraft.client.renderer.EntityRenderer

at net.minecraft.launchwrapper.LaunchClassLoader.findClass(LaunchClassLoader.java:179)

at java.lang.ClassLoader.loadClass(Unknown Source)

at java.lang.ClassLoader.loadClass(Unknown Source)

... 31 more

Caused by: java.lang.RuntimeException: Attempted to load class bfb for invalid side SERVER

at cpw.mods.fml.common.asm.transformers.SideTransformer.transform(SideTransformer.java:51)

at net.minecraft.launchwrapper.LaunchClassLoader.runTransformers(LaunchClassLoader.java:267)

at net.minecraft.launchwrapper.LaunchClassLoader.findClass(LaunchClassLoader.java:165)

... 33 more

[sEVERE] This crash report has been saved to: C:\Users\Adam Beasley\Desktop\MINECRAFT STUFF\Minecraft Server\.\crash-reports\crash-2013-07-10_11.08.31-server.txt