I have an appointment made by my gp to see a skin cancer specialist, to remove a lump, and see him in a month. should i be removing it sooner ?

Depends: Aside from the dreaded melanoma, which metastasizes quickly, the other major skin cancers usually proceed slowly, causing more local damage than metastasis. If the lesion isn't too large, a month wait would be reasonable; however, it's never a bad idea to get a second opinion if you are concerned.

Probably OK: Most skin cancers are slow growing. I am not all that familiar with the australian system, but from what i know - a month is not all that long.

Depends: For an isolated, small, non-aggressive skin cancer, 1 month is usually not an unreasonable amount of time to wait. If this is a dark spot with a melanoma diagnosis, if the lesion appears to be spreading fast, or if it is getting infected (red with or without drainage), you should seek medical attention from a dermatologist or plastic surgeon sooner.

Month: One month is probably okay. I generally tell my patients that once you have decided to operate, you should do it within a month.