There are many resources available to the potential Oleh - so many in fact that it can become difficult to know which are relevant and providing up-to-date information that can be relied upon.
Together with the Jewish Agency for Israel website, the list below gives a good general starting off point upon which to base your research.
AACI - The Association of Americans and Canadians in Israel - encouraging and assisting Aliyah from the USA and Canada since 1951
AACI Netanya - serving all English speakers in the Netanya area
Baltimore Chug Aliyah - a loose association of like-minded people considering aliyah from Baltimore and the surrounding area
ESCA - English Speakers' Club of Ashdod - social and cultural events for English speakers in Ashdod
ESRA - English Speaking Residents Association - enhancing the integration of English speakers into Israeli society
The Merkaz - Merkaz Hamagshimim Hadassah - Absorption, community and activism center aimed at 19 - 40 year old Olim - based in the heart of Jerusalem with offshoots in Tel Aviv
Ministry of Immigrant Absorption - the State of Israel's absorption aparatus - in many languages
NBN - Nefesh B'Nefesh - aiming to revitalize Aliyah and to substantially increase the number of future olim by removing the financial, professional and logistical obstacles that prevent many individuals from actualizing their dream
Tehilla - The voluntary movement for religious Aliyah