Despite the troubles within the country Malian tourist visas are being issued with minimal fuss. As long as you have a visa, getting in and out of the country via any of the main southern border crossings is fairly painless. Do not attempt to enter the country via Mauritania, Algeria or Niger.
Everyone but citizens of other West African countries needs a visa.
Visas are not available on arrival.
Visas are easy to get in most neighbouring countries.