Heading North from Athlone is Lough Ree and Glasson is about an hours cruise, a beautiful village known as 'the village of the roses'. There are a couple of good restaurants and pubs here. Glasson is also home to one of the best golf courses on the Shannon. You can moor your boat at Hodson Bay where you can have lunch or dinner in the Hodson Bay Hotel. You can moor your boat at the villages of Portrunny and Lecarrow while traversing the lake.
Two Hours from Glasson is Lanesborough/Ballyleague on the northern tip of Lough Ree. This town straddles the Shannon and the western side is Ballyleague in Roscommon and the eastern side is Lanesboro in Longford. There's a power station in Lanesborough and the hot water stretch just before Lough Ree is famous for fishing but note that stands are in great demand. This is the end of navigation for barges as they can't traverse the Lake.
The next town along the way is Tarmonbarry, with two good restaurants and one pub just after the lock. When you pass through Tarmonbarry Lock you can turn off for Clondra, at the end of the Royal Canal navigation.
About two hours from Tarmonbarry is Roosky with four pubs, one of which does Chinese food. There's a good supermarket here right on the waterside and nice mooring along the river as far as Roosky lock.
Dromod is less than an hour from Roosky. Dromod always does well in the national tidy towns competition and has a picturesque harbour on Lough Bofin. There's a restaurant right at the harbour and two pub/restaurants in the village, all good quality.
Heading North from Dromod the next town is Jamestown, about an hours cruising. Jamestown was once a fortified town and you can still see the remains of the fortification walls. There are two pubs here although one only opens sometimes, and a very good restaurant, the Cottage, about 10 minutes walk from the mooring.
If you like a bit of isolation and cruising then visit Kilglass and Grange lakes on the way down. There a nice pub at the end of Grange Lake called the Silver Eel. Kilglass Lake is home to Shannon River Adventure, and adventure centre with kayaking, canoeing, archery and other land and water based activities. There's a pub close to the adventure centre called the Kon Tiki but food isn't served.
It's about 7 hours cruising to Dromod and at this stage it's time to turn back to Athlone. If you have a couple of extra days you could head up to Carrick-on-Shannon, a vibrant town where both Carrick Craft and Emerald Star have bases. I can recommend Carrick Quads, about 40 minutes on a quad bike over courses of various difficulties. There are some good restaurants and pubs here and pretty much always music at weekends. There are also a couple of late bars with loud music if you like that sort of thing.