Good work, especially considering there doesn’t seem to be much aerial imagery available. Is it all from GPS surveys?

Some suggestions: You could check that area on Keep Right, it highlights a number of possible errors: http://keepright.ipax.at/report_map.php?lat=54.4492&lon=-6.33111&zoom=14 Also try using the JOSM validator.

eg I notice there are some untagged nodes, and some overlapping or unconnected roads. And some strange tagging, eg you have tagged all of the school area as building=yes, when presumably it is not all a building?

Also I notice the school/church etc are mapped as an area and a node. You should just have one and not the other (preferably an area). See osm.wiki/One_feature,_one_OSM_element

Great to hear you are interested in mapping charity shops, I have been mapping quite a few around here. First thing to do would be to find where they are, and add them to OSM. Sometimes it can be a bit tricky to find all of the obscure local shops!

I have made an example map of charity shops here (now a bit out of date): http://green.osmalba.org/charity.html Note you can click on the icons to get the name and details. It would be possible to use different icons for each charity etc. I can explain how to make something like that if you want.

The consensus in OSM is only to map roads as separate ways if they are physically separated. If it is just a white painted line, then they are not physically separate (even if it is illegal to drive across the line).

Yes, nodes which are not part of any ways or relations and which don't have any tags are an error. See osm.wiki/Untagged_unconnected_node
It is worth checking how old they are - if they only a few hours or days old, they might be from some sort of ongoing upload or import. But if they are much older, they are probably just a mistake, so best to delete them.

For feature requests, you add a ticket on Trac: http://trac.openstreetmap.org/
Set the component as "website".

I agree, it would be nice if the website could accept more kinds of coordinates.

You need to split both of the ways at the intersection node. ie select that node, then click the little scissors icon.
Then you should be able to set the streets for from and to.

Individual wifi access points are not usually mapped in OpenStreetMap. Because they are often temporary, and may be private etc.
There are a number of other websites where you can map wifi access points, eg http://openbmap.org/

Though if a business / amenity etc provides wifi (eg pub, cafe), then you can map the business in OpenStreetMap. Then tag that it provides internet access. See osm.wiki/Key:internet_access

I assume the roads cross at the same level, ie there isn't any bridge or tunnel?
If so, then the ways should cross with a shared node at the intersection.

And you should add turn restrictions, to specify that you are not allowed to turn off. Yes, Potlatch will show this with a little road sign symbol.
Its true you don't see that often in OSM, but that's because not many turn restrictions have been mapped yet (this will probably vary by area, there may some places with lots of turn restrictions mapped).

Most types of roads are two-way as default. There is no need to set this for each road. You only need to set the oneway option for the roads that are actually one way.

Note there are a few types of roads which might imply they are one-way, eg motorways, link roads etc. So it can be helpful to specifically set whether these are one-way or two-way.

Have you checked whether that council roads list is copyright?

There's some guidelines here: osm.wiki/Vandalism
Or this question: http://help.openstreetmap.org/questions/216/what-should-i-do-about-vandalism

The first thing to do would be to contact the user who changed/deleted it. It might just be a accident, or they might not realise they actually editing the map.
Also worth discussing it on the local mailing list or forum, to see what other mappers think.

The incorrect edits can be reverted if necessary.

If they continue to vandalise the map, then you can contact the data working group. The data working group can ban the user or revert all of their edits.

It sounds like most of those strange anomalies are from the US TIGER import. osm.wiki/TIGER
It can be very inaccurate or out of date in some places. You can look at any source tags, or the history of the objects to check where its from. Its probably not jokers or vandals, just wrong official government data. TIGER data in OSM should be checked and fixed where possible.

Also despite the name, OpenStreetMap is not just a street map. There is loads of other geographical data in the project, and it is welcome. Database clutter is not really a problem, extra detail doesn't really slow down rendering.

Though if you have something like a small pond mapped with hundreds or thousands of nodes that would probably be excessive. That sort of thing is probably from an unhelpful import, eg TIGER.

I think it is all correct, its just Mapnik hadn't rerendered those tiles. I have marked those tiles as dirty, which caused them to be rendered.
And its showing the courtyard now.

Also, if you want data for a large area, you should probably use a Planet extract: osm.wiki/Planet#Country_and_area_extracts
These are available for a number of countries or regions.

The Planet extract contains all of the OSM data for that area. If you only want the data for roads, then you can process the extract to filter out what you do/don't want. For software to use for this, you could use Osmfilter osm.wiki/Osmfilter or Osmosis osm.wiki/Osmosis

It is not a question of whether the coordinates are an error or not. It is a matter of copyright. See this page: osm.wiki/Copyright
Specifically "Do not use data from copyrighted maps or any other proprietary data!"

It is not clear whether those coordinates from Wikipedia are from copyrighted maps (eg Google Maps) or not. So please don't add them to OpenStreetMap.

Many of the coordinates in Wikipedia are actually copied from other sources, which may be copyright. A lot has been copied from Google Maps, or from various national mapping agencies (eg the Ordnance Survey in Great Britain).
So they are not actually under a suitable licence for copying/importing to OpenStreetMap.

See this page: osm.wiki/Collaboration_with_Wikipedia#Importing_geodata_from_Wikipedia

I agree that the Tracks/Mapped/Labelled columns are not really very useful.

Though I think a single column for completeness is a bit simplistic. Some people are setting it to 100% just because the length of ways in the route relation is equal to the 'official' distance. Without actually walking the route to check whether it is actually correct.

Also, even if the route is correct, is it all tagged correctly? ie I've noticed quite a few parts of routes tagged as highway=track, when they actually paths or minor roads etc. And then there's tags for access, surface, tracktype etc.
Plus facilities along the route, eg toilets, drinking water, shops, cafes, campsites etc.

So I don't think a route is really "complete" unless most of this has been done.

For Garmin maps, I recommend this website: http://garmin.openstreetmap.nl/
Pick the country from the drop down lists, then enter your email address and click build my map.
You will soon get sent a link to download the map. This includes a version with a MapSource installer (called osm_routable_mapsource.exe), so download and run that, and the maps will appear in MapSource. You can then load the maps onto your Garmin GPS device.

Maybe the GPStogo scheme could help, by loaning some GPS devices? http://www.osmfoundation.org/wiki/GPStogo

See this page for a recommended procedure for Naptan bus stops: osm.wiki/NaPTAN/Surveying_and_Merging_NaPTAN_and_OSM_data

Also, there is a JOSM style which can highlight Naptan bus stops, and whether they have been verified (similar to that Novam tool). See http://josm.openstreetmap.de/wiki/Styles