A google for linux assembly returns some useful links. Here's one version of x86 hello world for gcc (gas assembler):
Code:
13:54 aluser@alf:~/asm$ cat helloworld.s
.data
msg:
.asciz "Hello, World!\n"
.text
.globl main
main:
push %ebp
movl %esp, %ebp
pushl $msg
call printf
leave
ret
13:54 aluser@alf:~/asm$ gcc -o helloworld helloworld.s
13:54 aluser@alf:~/asm$ ./helloworld
Hello, World!
13:54 aluser@alf:~/asm$
There are of course many ways to skin the same cat.