can i do this, will the paper be enough to isolate and not cause shorts?
You don't even need paper - there are plenty of examples out there of circuits built with just the parts and solder holding them together; nothing but air in-between. In fact, LED cubes are a prime example of this kind of construction - but there are examples out there done in this manner as an artistic effort.
That said, even a single sheet of typing paper would have enough insulation to allow two uninsulated wires on each side to cross and not cause issues (at least, conductivity issues).
are there any examples out there, i cant seem to find any..
You may not have been using the right search terms (seeing as english isn't your primary language?) - I just googled for "paper PCB" and found this link, entitled "Foldable Printed Circuit Boards on Paper Substrates":http://gmwgroup.harvard.edu/pubs/pdf/1075.pdf
It's kinda interesting - a bit more technical than what you are probably looking for, but they show circuit traces and such applied to folded origami cranes...
Of course, the biggest problem when searching for something like "paper" and "PCB" together, is the sheer number of how-to articles dealing with -etching- a standard PCB using a laser printer and the toner transfer method (not at all what you are looking for).
Here's another interesting link:http://popsci.typepad.com/how20blog/2007/10/ppcbs-aka-paper.html
will the paper burn just because an electrical current is flowing realy nearby?
It shouldn't be a problem as long as your circuit isn't pulling a lot of current; based on what you've specified as possible parts, it likely wouldn't be an issue.
any tips before i actuly try this?
Well - I would continue to do more research. For instance, did you know that there are standard PCBs out there made with paper as a base?http://www.felsweb.com/lam_faq.htm#F
FR2 and FR3 use cotton paper as the base for the board; the difference between the two is that FR2 uses a phenolic binder, while FR3 uses an epoxy binder. If you continue to read down that page, you'll see a question reading "Can I make my own FR4?"...
In short - what you want to do isn't impossible; in fact, it is probably quite "doable". I would personally do it in something like this manner:
1. Print out my circuit on a printer on thick paper.
2. Use two-part clear epoxy to glue the paper to non-corrugated cardboard.
3. Use more epoxy to coat the front and back of the cardboard/paper sandwich.
4. Drill holes where the components will be inserted.
5. Insert the components - maybe some hot-glue dabs to keep them in place.
6. Wire/solder the parts together.
If you give it some more thought, you can probably come up with ways to put down "traces"; you can try copper foil tape (don't use aluminium foil, you can't solder to it) - there is also silver-bearing "wire glues" out there, as well as tapes and paints meant for repairing windshield defrosters (this stuff isn't cheap, though). You could just take solid copper wire, remove the insulating, then shape/flatten it with a hammer on an anvil and glue it down on the board.
Such boards should work fine - they won't look pretty, of course - but likely no worse than early electronics. In fact, you might want to read up on the history of electronics and such for more inspiration/ideas:http://en.wikipedia.org/wiki/Printed_circuit_boardhttp://en.wikipedia.org/wiki/Point-to-point_construction
Good luck - hope this helps!