violation reading location

In the first code snippet, strcpy(node->name,name) leads to an access violation since node does not hold the address of any valid memory location.

[EDIT1]
Looking again at your homework code shows that you have several flawas in your code:

1) Saving and loading are not symetric in your implementation: save tries to store first the seconds and only then the name while loading tries to load first the name and then the seconds.
2) You seem to confuse sizeof() with strlen() for the name.
3) You can only use fread for reading the name if the name has always a fixed length.
4) Why do you store the data as binary file? Why not text (save: fprintf(fp, "%f %s\n", node->second, node->name);, load: fscanf(fp, "%f %s\n", &seconds, buffer);).
5) Why don't you employ the add function to add a node in the load function?
6) The load function is broken: you try to read all records from the file, but don't add each record within the while loop.
7) In save, you do not close the file in all control branches - move it out of the if block.
8) You use the list_head inconsistently: once you modify it and invalidate it as such (e.g. in the save function, while in the load function you do not reset it before loading.
9) Please try to give meaningul names from the beginning of your career: temp, plain or in any combined form, is crap. If you fail to give a decent name you probably have not understood the task at hand. Why don't you name it node_to_add or alike?

[/EDIT1]

Cheers
Andi