Hi Mo,
To be honest I would not bother. It is difficult to get a good permanent preparation without a lot of effort and experience - especially of a subject that contains so much water. In most methods the specimen has to be dehydrated using a series of increasing strengths of alcohol. Another problem with your alga is that you will probably lose the green colour either through bleaching with time or leaching out in the alcohol. Some subjects eg your "bee bits" are much easier to prepare and I think would be worth a go.
There are number of articles on making permanent mounts in micscape magazine:
http://www.microscopy-uk.org.uk/index.html
and then go to the search tool
I do store samples of micro-algae for later examination. I normally use iodine - preferably Lugols Iodine - but usually "tincture of iodine" added to a glass tube containing the sample - just enough to get a weak tea colour. Parts of the algae will stain brown or black. Store in the dark and you may have to top up the iodine periodically as it evaporates. Alternatively you could use formaldehyde (formalin) instead of iodine. This wont stain the cells and if kept in the dark the algae may retain the green colour for quite some time.
For me, preserved algae and other aquatic specimens are nowhere near as interesting as the live ones.
Good luck with your efforts.
Ciao
brianO