There are two aspects to your question, so I've addressed them individually.
Keywords in the URL
When all other factors are equal, a web page with the keyword in the
URL (especially the domain name) will rank higher than one that
The most important aspect of this is that if the words are all joined
together, as in skichaletfinders.com, then it will only make a
difference if someone searches for the word skichaletfinders. For a
multi-word domain name to affect search ranking it needs to have
hyphens between each word.
It is quite noticable in search results that keyword URLs do well.
Most of the advantage comes from links to the site that use its name.
For example, if your site is called blackorbluewidgets.com, I would
link to it using "Black or Blue Widgets", if that is the name of your
site (as presented in the logo and/or title).
But for the algorithm to give extra points to a site for keywords in
the domain name, you need hyphens. The very big downside to this is
that as search engine users become more experienced, they are
realising that hyphenated-domain-names tend to be spammy. Which means
they are less likely to visit your site.
Plural or not?
Google uses stemming - when you search for a word, Google will provide
results that contain almost matches to that word, including plurals.
This is recent - Google originally only found precise matches. From
reading posts at WebMasterWorld.com I have formed an opinion that the
weight given by Google to stemming varies considerably from time to
time. Sometimes they appear to have switched it off. There is no way
of telling at present if using the plural as your main keyword is a
good or bad move.
Keywords in links to your site are more powerful than having them in
the URL. Having hyphens in your URL looks spammy.
I suggest that you stick with your current URL, but rename your site.
Instead of the name of your site being chaletfinders.com, call it
"Chalet Finders". That way you get the power of having the keyword
"chalet" in the page title and in links to your site.
Even better would be to use skichaletfinders.com, and calling your
site "Ski Chalet Finders" - having two keywords in the domain is
better, but the downside is the work involved to change the URL of
Finders isn't really a keyword, so it doesn't matter that it is
plural. If you think the plural sounds better, keep it.
If any part of my answer is unclear, or if you have further questions
on this topic, just request a clarification and I'll get back to you.