Here, this should help
1. Your model must be triangulated(converted to triangles) before you export it.
Hold CTRL + F while in edit mode to make a menu with options for faces appear and click on the triangulate option
2.before exporting your model must have a blender internal render type material(so no cycles) assigned to it,just leave it at default for the material settings or perhaps tone down the spec if it gets annoying while editting. REMEMBER: only one material per object or crash.
3.Before exporting you model it must have a texture assigned to it, with UV cordinates. so make sure to set it to UV cordinates under mapping in the texture tab. only one texture per object as well.
4. make sure your object is at the center when you export. you can do that by first holding SHIFT + S and clicking cursor to center, and then doing the same but clicking selection to cursor instead.
This step is not necesary but your objects pivot point/origin will be at the center when exported to amnesia so it can get hard to work with if you dont do this step.
5. Apply scale rotation and location of your object by going to the apply menu by holding down CTRL + A and rest is self explanatory. this step is not necesary but it will prevent you model from being rotated, scaled or offset in amnesia.
6.Make sure your face normals are right before exporting or you will have what looks like holes in yout object in amnesia. If you click N to bring forth the navigation menu you will find an option called "Backface Culling" under display, this will only render the front of your objects faces just like in amnesia.
To fix a face that is facing the wrong way select it in edit mode, hit W to bring up the specials menu and click "flip normals".
EXPORT:
1.Go to file -> Export -> Collada (Default) (.dae)
2. find the desired location to export your model to. it must be within the amnesia folder.
3.Name your model, it is recommended that give its name an extension iconic to your CS/Mod so amnesia doesent mess up if someone has a mod with another object under the same name. Fx if you had a CS/Mod called banana attack with a chair you would name it chair_ba.dae, rather then chair.dae which would likely be messed up with another chair.
4.Before exporting there is some settings in the lower left corner I would like to go through:
Apply modifiers: applies your modifiers automatically, though I recommend doing everything manually before exporting since you cant always rely on these automatic feutures.
Selection Only: makes it so that only your selected objects are exported, I always use this option but you can work without it if you delete everything but what you are exporting from your scene. I like to have some lights around though so I find that unpractical.
Include Children: dunno exacly what this does but in terms of amnesia exporting this should always be unchecked.
Inlclude armatures: this is for exporting rigged models with skeletons, which are called armatures in blender. as far as I know no one has been able to export animated models from any other software then maya so I dont think you will ever need this option checked.
Inlcude Shape Keys: amnesia does not support shape keys only skeletons so this should be unchecked. mostly its not necesary to uncheck it though since mostly you wont even have any shape keys on you model.
Only Active UV layer:this should be unchecked
Include UV textures: this option is lethal, it will write what textures your model is using into the collada file, if you dont use this check box amnesia will likely crash.
Include material textures: uncheck this, amnesia is only UV textures.
Copy: Whether you are going to use this or not depends on where your textures are stored. if you have texture from outside the Amnesia/redist folder assigned to your model when exporting you should check this option. it will copy your textures to the location you are exporting to. if you already have your textures in the right location leave this unchecked.
Deform bones only: uncheck this
Export for second life: uncheck this
Use object indtances: not exacly 100% sure about this option but I have allways had it checked with no problems at all.
Sort by object name: always had this unchecked, b