DotLucene is the engine behind search in Sitecore client. Sitecore itself provides most common patterns of advanced search, allowing to specify ‘created/updated’ date interval, or filter by author.

Here’s how search query looks like when searching for items authored by ‘Admin’ user: author:"sitecore\Admin".
In lucene terms it says to look for documents containing ‘sitecore\Admin’ in ‘author’ field. Don’t confuse lucene’s fields with those of Sitecore, though. To see which fields are there for you to search by (and to add own ones, if you fancy) refer to ‘system’ index declaration in web.config:

<index id="system" singleInstance="true" type="Sitecore.Data.Indexing.Index, Sitecore.Kernel">
  <param desc="name">$(id)</param>
  <fields hint="raw:AddField">
    <field target="created">__created</field>
    <field target="updated">__updated</field>
    <field target="author">__updated by</field>
    <field target="published">__published</field>
    <field target="name">@name</field>
    <field storage="unstored">@name</field>
    <field target="template">@tid</field>
    <field target="id" storage="unstored">@id</field>
    <type storage="unstored">memo</type>
    <type storage="unstored">text</type>
    <type storage="unstored" stripTags="true">html</type>
    <type storage="unstored" stripTags="true">rich text</type>
  </fields>
</index>

And finally, refer to DotLucene Query Syntax for more options, including wildcard and ‘fuzzy’ searches. And since Sitecore 5.3 uses asynchronous search index updates, there’s much less incentive to turn the indexing off.