Install lots TS3
Da SimsCri Simpedia.
You can find 2 different file type to identify installable lot: .sims3pack or .package. It is better to install only lots available as .sims3pack.
If the file is Sims3Pack
You can find full instruction on how to install .sims3packfiles HERE Once installed they are stored into Library (My Documents/Electronic Arts/The Sims 3/Library) and another file into DCBackups (My Documents/Electronic Arts/The Sims 3/DCBackups)
If the file is .package
You should find 2 files, with instruction about where put them. You should insert the files directly into Library (My Documents/Electronic Arts/The Sims 3/Library) and another file into DCBackups (My Documents/Electronic Arts/The Sims 3/DCBackups). If you find just one file, probably it goes to Library