Negotiating this area is easy except in July and August, when the roads around Oban may be congested. There are a number of single-lane roads, especially on the east side of the Kintyre Peninsula and on the islands, which require special care. Remember that white triangles indicate places where you can pass. You'll probably have to board a ferry at some point during your trip; nearly all ferries take cars as well as pedestrians.
From Glasgow, take the A82 and the A85 to Oban, the main ferry terminal for Mull and the islands (about 2½ hours by car). From the A82, take the A83 at Arrochar; it rounds Loch Fyne to Inveraray. From there you can take the A819 from Inveraray around Loch Awe and rejoin the Glasgow–Oban road. Alternatively, you can stay on the A83 and head down Kintyre to Kennacraig, the ferry terminal for Islay. Farther down the A83 is Tayinloan, the ferry port for Gigha. You can reach Brodick on Arran by ferry from Ardrossan, on the Clyde coast (M8/A78 from Glasgow); in summer you can travel to Lochranza from Claonaig on the Kintyre Peninsula, but there are very few crossings.