Hi Brian, check out my two blog posts here --> https://community.emc.com/community/connect/isilon/blog/2013/09/25/using-powershell-with-the-papi-and-ran--the-basics to get all the info you'll need to get started with Powershell and the API.  I'm also going to post below here the code you would need to create a share.  If for some reason the formatting makes it difficult, just email me directly and I'll send you the .ps1 file.

Thanks!

######################################################################################################################################################
#
# Created: 09/30/2013  by Jeremy Smith, EMC NAS Specialist Central Division
# Modified:
#
#
# ps_isilon_create_share_via_papi.ps1 - create a share
# Note: You need to be at OneFS 7 or greater to leverage the PAPI and HTTP Access must be enabled on the cluster.
#
# PARAMETERS
#
# -isilonip = node IP
# -username
# -password
# -path = /ifs directory path for share
# -name = share name
#
#
# EXAMPLE
# .\ps_isilon_create_share_via_papi.ps1  -isilonip 10.10.10.1 -user root -password a -path /ifs/data/test -name "test$"
#
#
########################################################################################################################################

# Accept input parameters
Param([String]$isilonip,[String]$username,[String]$password,[String]$path,[String]$name)

# With a default cert you would normally see a cert error (code from blogs.msdn.com)
add-type @"
using System.Net;
using System.Security.Cryptography.X509Certificates;

    public class TrustAll : ICertificatePolicy {
    public TrustAll() {}
    public bool CheckValidationResult(
        ServicePoint sPoint, X509Certificate cert,
        WebRequest req, int problem) {
        return true;
    }
}
"@
[System.Net.ServicePointManager]::CertificatePolicy = new-object TrustAll

#if the correct parameters were not passed we exit after a message
if (!($isilonip -and $username -and $password -and $path -and $name)) {
   write "failed to specify parameters";
   write "Example: .\ps_isilon_set_quotas_via_papi.ps1 -isilonip 192.168.1.2 -username root -password a -path /ifs/data/jeremy/test -name testshare";
   exit
}

# Encode basic authorization header and create baseurl
$EncodedAuthorization = [System.Text.Encoding]::UTF8.GetBytes($username + ':' + $password)
$EncodedPassword = [System.Convert]::ToBase64String($EncodedAuthorization)
$headers = @{"Authorization"="Basic $($EncodedPassword)"}
$baseurl = 'https://' + $isilonip +":8080"

Write-Host " "

# Create share
$resource = "/platform/1/protocols/smb/shares"
Write-Host "Creating a share at $path called $name"
$ShareObject = @"
{"name":"$name", "path": "$path"}
"@

$headers = @{"Authorization"="Basic $($EncodedPassword)"}
$uri = $baseurl + $resource
$ISIObject2 = Invoke-RestMethod -Uri $uri -Headers $headers -Body $ShareObject -ContentType "application/json; charset=utf-8" -Method POST
$ISIObject2
Write-Host "`nDone!"