I’ve been having a lot of trouble doing curves lately. The main one is that when i try to smove them off on a 3d object using the subsurf modifier it’s keeps on messing up whatever i’m making.
Just as an example, this is what happens when i apply it to a curved sword blade.
I’m still pretty new to blender, i’ve only had it for a few days so i might just be making some stupid mistake, but i’d really apreciate it if anybody could tell me what i’m doing wrong, and how to fix it.
Well known annoyance. Twisted curves. 
It’s when normal gets tilted past a certain point, and it flips to the other side. You can correct it a few ways, although for such a small item, manually is really fast…
Read the very last tip on this page (at the bottom): http://www.blender.org/modules/documentation/htmlI/x4047.html
If you want to know how to fix it on a case-by-case basis instead of the whole thing at once, go into Edit mode, grab one of the control points in question, press T, and start moving the mouse in the direction needed to “unwrap” the twist. It will be apparent once you move the mouse.
You can search here for terms like “twisted curve”, “dreaded Z axis”, etc.
Thanks for that, but i forgot the mention that i had made this using single points which is smothed out, rather than one of the curves because i couldnt work out how to do the filling properly. So does that change anything? or do i still fix it the same way?
EDIT: Ok, i found out how to change the curves into a mesh rather than plotting all of the points myself, but when i use subsurf using that method it goes kinda wrinkly. Is there any way to stop this?
Yes, it changes everything. 
What I’m referring to only affects curves and control points, not meshes and vertices. There’s no Tilt option for vertices, it’s just called Rotate (and you can’t really rotate a single vertex, it needs at least one other to have spatial reference, but I digress)
I jumped the gun w/o reading your post. You clearly state “subsurf” which you can’t do to a curve.
Sometimes meshes get all wonky. Normals get messed up, etc. That looks exactly like the curve normal twisted issue, so I’m guessing you had an interior vertex or 5 and when you subsurf’d it smoothed to them too.
Could you post a screenshot in Edit mode, so we can see the vertices? (and not for nothing, but some of us are running huge screens like 1920x1440, so 320x200 images are thumbnail sized and we can’t see details )
Also, subsurf’ing a thing you want to be hard-edged will require you to crease. As for it looking splotchy, it could be a lot of things, recalculate normals outside first (Ctrl-N) and see if that helps… sometimes it just mangles your mesh and you have to tweak it.